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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 bool
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 false;
149
150 if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid))
151 return false;
152 if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn)
153 return false;
154 if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->info.lsn)))
155 return false;
156 } else {
157 if (ichdr.magic != XFS_DA_NODE_MAGIC)
158 return false;
159 }
160 if (ichdr.level == 0)
161 return false;
162 if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
163 return false;
164 if (ichdr.count == 0)
165 return false;
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 false;
174
175 /* XXX: hash order check? */
176
177 return true;
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_fspriv;
186 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
187
188 if (!xfs_da3_node_verify(bp)) {
189 xfs_buf_ioerror(bp, -EFSCORRUPTED);
190 xfs_verifier_error(bp);
191 return;
192 }
193
194 if (!xfs_sb_version_hascrc(&mp->m_sb))
195 return;
196
197 if (bip)
198 hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
199
200 xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
201}
202
203/*
204 * leaf/node format detection on trees is sketchy, so a node read can be done on
205 * leaf level blocks when detection identifies the tree as a node format tree
206 * incorrectly. In this case, we need to swap the verifier to match the correct
207 * format of the block being read.
208 */
209static void
210xfs_da3_node_read_verify(
211 struct xfs_buf *bp)
212{
213 struct xfs_da_blkinfo *info = bp->b_addr;
214
215 switch (be16_to_cpu(info->magic)) {
216 case XFS_DA3_NODE_MAGIC:
217 if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
218 xfs_buf_ioerror(bp, -EFSBADCRC);
219 break;
220 }
221 /* fall through */
222 case XFS_DA_NODE_MAGIC:
223 if (!xfs_da3_node_verify(bp)) {
224 xfs_buf_ioerror(bp, -EFSCORRUPTED);
225 break;
226 }
227 return;
228 case XFS_ATTR_LEAF_MAGIC:
229 case XFS_ATTR3_LEAF_MAGIC:
230 bp->b_ops = &xfs_attr3_leaf_buf_ops;
231 bp->b_ops->verify_read(bp);
232 return;
233 case XFS_DIR2_LEAFN_MAGIC:
234 case XFS_DIR3_LEAFN_MAGIC:
235 bp->b_ops = &xfs_dir3_leafn_buf_ops;
236 bp->b_ops->verify_read(bp);
237 return;
238 default:
239 xfs_buf_ioerror(bp, -EFSCORRUPTED);
240 break;
241 }
242
243 /* corrupt block */
244 xfs_verifier_error(bp);
245}
246
247const struct xfs_buf_ops xfs_da3_node_buf_ops = {
248 .name = "xfs_da3_node",
249 .verify_read = xfs_da3_node_read_verify,
250 .verify_write = xfs_da3_node_write_verify,
251};
252
253int
254xfs_da3_node_read(
255 struct xfs_trans *tp,
256 struct xfs_inode *dp,
257 xfs_dablk_t bno,
258 xfs_daddr_t mappedbno,
259 struct xfs_buf **bpp,
260 int which_fork)
261{
262 int err;
263
264 err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
265 which_fork, &xfs_da3_node_buf_ops);
266 if (!err && tp) {
267 struct xfs_da_blkinfo *info = (*bpp)->b_addr;
268 int type;
269
270 switch (be16_to_cpu(info->magic)) {
271 case XFS_DA_NODE_MAGIC:
272 case XFS_DA3_NODE_MAGIC:
273 type = XFS_BLFT_DA_NODE_BUF;
274 break;
275 case XFS_ATTR_LEAF_MAGIC:
276 case XFS_ATTR3_LEAF_MAGIC:
277 type = XFS_BLFT_ATTR_LEAF_BUF;
278 break;
279 case XFS_DIR2_LEAFN_MAGIC:
280 case XFS_DIR3_LEAFN_MAGIC:
281 type = XFS_BLFT_DIR_LEAFN_BUF;
282 break;
283 default:
284 type = 0;
285 ASSERT(0);
286 break;
287 }
288 xfs_trans_buf_set_type(tp, *bpp, type);
289 }
290 return err;
291}
292
293/*========================================================================
294 * Routines used for growing the Btree.
295 *========================================================================*/
296
297/*
298 * Create the initial contents of an intermediate node.
299 */
300int
301xfs_da3_node_create(
302 struct xfs_da_args *args,
303 xfs_dablk_t blkno,
304 int level,
305 struct xfs_buf **bpp,
306 int whichfork)
307{
308 struct xfs_da_intnode *node;
309 struct xfs_trans *tp = args->trans;
310 struct xfs_mount *mp = tp->t_mountp;
311 struct xfs_da3_icnode_hdr ichdr = {0};
312 struct xfs_buf *bp;
313 int error;
314 struct xfs_inode *dp = args->dp;
315
316 trace_xfs_da_node_create(args);
317 ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
318
319 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, whichfork);
320 if (error)
321 return error;
322 bp->b_ops = &xfs_da3_node_buf_ops;
323 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
324 node = bp->b_addr;
325
326 if (xfs_sb_version_hascrc(&mp->m_sb)) {
327 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
328
329 memset(hdr3, 0, sizeof(struct xfs_da3_node_hdr));
330 ichdr.magic = XFS_DA3_NODE_MAGIC;
331 hdr3->info.blkno = cpu_to_be64(bp->b_bn);
332 hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
333 uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid);
334 } else {
335 ichdr.magic = XFS_DA_NODE_MAGIC;
336 }
337 ichdr.level = level;
338
339 dp->d_ops->node_hdr_to_disk(node, &ichdr);
340 xfs_trans_log_buf(tp, bp,
341 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
342
343 *bpp = bp;
344 return 0;
345}
346
347/*
348 * Split a leaf node, rebalance, then possibly split
349 * intermediate nodes, rebalance, etc.
350 */
351int /* error */
352xfs_da3_split(
353 struct xfs_da_state *state)
354{
355 struct xfs_da_state_blk *oldblk;
356 struct xfs_da_state_blk *newblk;
357 struct xfs_da_state_blk *addblk;
358 struct xfs_da_intnode *node;
359 int max;
360 int action = 0;
361 int error;
362 int i;
363
364 trace_xfs_da_split(state->args);
365
366 /*
367 * Walk back up the tree splitting/inserting/adjusting as necessary.
368 * If we need to insert and there isn't room, split the node, then
369 * decide which fragment to insert the new block from below into.
370 * Note that we may split the root this way, but we need more fixup.
371 */
372 max = state->path.active - 1;
373 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
374 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
375 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
376
377 addblk = &state->path.blk[max]; /* initial dummy value */
378 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
379 oldblk = &state->path.blk[i];
380 newblk = &state->altpath.blk[i];
381
382 /*
383 * If a leaf node then
384 * Allocate a new leaf node, then rebalance across them.
385 * else if an intermediate node then
386 * We split on the last layer, must we split the node?
387 */
388 switch (oldblk->magic) {
389 case XFS_ATTR_LEAF_MAGIC:
390 error = xfs_attr3_leaf_split(state, oldblk, newblk);
391 if ((error != 0) && (error != -ENOSPC)) {
392 return error; /* GROT: attr is inconsistent */
393 }
394 if (!error) {
395 addblk = newblk;
396 break;
397 }
398 /*
399 * Entry wouldn't fit, split the leaf again. The new
400 * extrablk will be consumed by xfs_da3_node_split if
401 * the node is split.
402 */
403 state->extravalid = 1;
404 if (state->inleaf) {
405 state->extraafter = 0; /* before newblk */
406 trace_xfs_attr_leaf_split_before(state->args);
407 error = xfs_attr3_leaf_split(state, oldblk,
408 &state->extrablk);
409 } else {
410 state->extraafter = 1; /* after newblk */
411 trace_xfs_attr_leaf_split_after(state->args);
412 error = xfs_attr3_leaf_split(state, newblk,
413 &state->extrablk);
414 }
415 if (error)
416 return error; /* GROT: attr inconsistent */
417 addblk = newblk;
418 break;
419 case XFS_DIR2_LEAFN_MAGIC:
420 error = xfs_dir2_leafn_split(state, oldblk, newblk);
421 if (error)
422 return error;
423 addblk = newblk;
424 break;
425 case XFS_DA_NODE_MAGIC:
426 error = xfs_da3_node_split(state, oldblk, newblk, addblk,
427 max - i, &action);
428 addblk->bp = NULL;
429 if (error)
430 return error; /* GROT: dir is inconsistent */
431 /*
432 * Record the newly split block for the next time thru?
433 */
434 if (action)
435 addblk = newblk;
436 else
437 addblk = NULL;
438 break;
439 }
440
441 /*
442 * Update the btree to show the new hashval for this child.
443 */
444 xfs_da3_fixhashpath(state, &state->path);
445 }
446 if (!addblk)
447 return 0;
448
449 /*
450 * xfs_da3_node_split() should have consumed any extra blocks we added
451 * during a double leaf split in the attr fork. This is guaranteed as
452 * we can't be here if the attr fork only has a single leaf block.
453 */
454 ASSERT(state->extravalid == 0 ||
455 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
456
457 /*
458 * Split the root node.
459 */
460 ASSERT(state->path.active == 0);
461 oldblk = &state->path.blk[0];
462 error = xfs_da3_root_split(state, oldblk, addblk);
463 if (error) {
464 addblk->bp = NULL;
465 return error; /* GROT: dir is inconsistent */
466 }
467
468 /*
469 * Update pointers to the node which used to be block 0 and just got
470 * bumped because of the addition of a new root node. Note that the
471 * original block 0 could be at any position in the list of blocks in
472 * the tree.
473 *
474 * Note: the magic numbers and sibling pointers are in the same physical
475 * place for both v2 and v3 headers (by design). Hence it doesn't matter
476 * which version of the xfs_da_intnode structure we use here as the
477 * result will be the same using either structure.
478 */
479 node = oldblk->bp->b_addr;
480 if (node->hdr.info.forw) {
481 ASSERT(be32_to_cpu(node->hdr.info.forw) == addblk->blkno);
482 node = addblk->bp->b_addr;
483 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
484 xfs_trans_log_buf(state->args->trans, addblk->bp,
485 XFS_DA_LOGRANGE(node, &node->hdr.info,
486 sizeof(node->hdr.info)));
487 }
488 node = oldblk->bp->b_addr;
489 if (node->hdr.info.back) {
490 ASSERT(be32_to_cpu(node->hdr.info.back) == addblk->blkno);
491 node = addblk->bp->b_addr;
492 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
493 xfs_trans_log_buf(state->args->trans, addblk->bp,
494 XFS_DA_LOGRANGE(node, &node->hdr.info,
495 sizeof(node->hdr.info)));
496 }
497 addblk->bp = NULL;
498 return 0;
499}
500
501/*
502 * Split the root. We have to create a new root and point to the two
503 * parts (the split old root) that we just created. Copy block zero to
504 * the EOF, extending the inode in process.
505 */
506STATIC int /* error */
507xfs_da3_root_split(
508 struct xfs_da_state *state,
509 struct xfs_da_state_blk *blk1,
510 struct xfs_da_state_blk *blk2)
511{
512 struct xfs_da_intnode *node;
513 struct xfs_da_intnode *oldroot;
514 struct xfs_da_node_entry *btree;
515 struct xfs_da3_icnode_hdr nodehdr;
516 struct xfs_da_args *args;
517 struct xfs_buf *bp;
518 struct xfs_inode *dp;
519 struct xfs_trans *tp;
520 struct xfs_dir2_leaf *leaf;
521 xfs_dablk_t blkno;
522 int level;
523 int error;
524 int size;
525
526 trace_xfs_da_root_split(state->args);
527
528 /*
529 * Copy the existing (incorrect) block from the root node position
530 * to a free space somewhere.
531 */
532 args = state->args;
533 error = xfs_da_grow_inode(args, &blkno);
534 if (error)
535 return error;
536
537 dp = args->dp;
538 tp = args->trans;
539 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
540 if (error)
541 return error;
542 node = bp->b_addr;
543 oldroot = blk1->bp->b_addr;
544 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
545 oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
546 struct xfs_da3_icnode_hdr icnodehdr;
547
548 dp->d_ops->node_hdr_from_disk(&icnodehdr, oldroot);
549 btree = dp->d_ops->node_tree_p(oldroot);
550 size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
551 level = icnodehdr.level;
552
553 /*
554 * we are about to copy oldroot to bp, so set up the type
555 * of bp while we know exactly what it will be.
556 */
557 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
558 } else {
559 struct xfs_dir3_icleaf_hdr leafhdr;
560 struct xfs_dir2_leaf_entry *ents;
561
562 leaf = (xfs_dir2_leaf_t *)oldroot;
563 dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
564 ents = dp->d_ops->leaf_ents_p(leaf);
565
566 ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
567 leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
568 size = (int)((char *)&ents[leafhdr.count] - (char *)leaf);
569 level = 0;
570
571 /*
572 * we are about to copy oldroot to bp, so set up the type
573 * of bp while we know exactly what it will be.
574 */
575 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
576 }
577
578 /*
579 * we can copy most of the information in the node from one block to
580 * another, but for CRC enabled headers we have to make sure that the
581 * block specific identifiers are kept intact. We update the buffer
582 * directly for this.
583 */
584 memcpy(node, oldroot, size);
585 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
586 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
587 struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
588
589 node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
590 }
591 xfs_trans_log_buf(tp, bp, 0, size - 1);
592
593 bp->b_ops = blk1->bp->b_ops;
594 xfs_trans_buf_copy_type(bp, blk1->bp);
595 blk1->bp = bp;
596 blk1->blkno = blkno;
597
598 /*
599 * Set up the new root node.
600 */
601 error = xfs_da3_node_create(args,
602 (args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
603 level + 1, &bp, args->whichfork);
604 if (error)
605 return error;
606
607 node = bp->b_addr;
608 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
609 btree = dp->d_ops->node_tree_p(node);
610 btree[0].hashval = cpu_to_be32(blk1->hashval);
611 btree[0].before = cpu_to_be32(blk1->blkno);
612 btree[1].hashval = cpu_to_be32(blk2->hashval);
613 btree[1].before = cpu_to_be32(blk2->blkno);
614 nodehdr.count = 2;
615 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
616
617#ifdef DEBUG
618 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
619 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
620 ASSERT(blk1->blkno >= args->geo->leafblk &&
621 blk1->blkno < args->geo->freeblk);
622 ASSERT(blk2->blkno >= args->geo->leafblk &&
623 blk2->blkno < args->geo->freeblk);
624 }
625#endif
626
627 /* Header is already logged by xfs_da_node_create */
628 xfs_trans_log_buf(tp, bp,
629 XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
630
631 return 0;
632}
633
634/*
635 * Split the node, rebalance, then add the new entry.
636 */
637STATIC int /* error */
638xfs_da3_node_split(
639 struct xfs_da_state *state,
640 struct xfs_da_state_blk *oldblk,
641 struct xfs_da_state_blk *newblk,
642 struct xfs_da_state_blk *addblk,
643 int treelevel,
644 int *result)
645{
646 struct xfs_da_intnode *node;
647 struct xfs_da3_icnode_hdr nodehdr;
648 xfs_dablk_t blkno;
649 int newcount;
650 int error;
651 int useextra;
652 struct xfs_inode *dp = state->args->dp;
653
654 trace_xfs_da_node_split(state->args);
655
656 node = oldblk->bp->b_addr;
657 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
658
659 /*
660 * With V2 dirs the extra block is data or freespace.
661 */
662 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
663 newcount = 1 + useextra;
664 /*
665 * Do we have to split the node?
666 */
667 if (nodehdr.count + newcount > state->args->geo->node_ents) {
668 /*
669 * Allocate a new node, add to the doubly linked chain of
670 * nodes, then move some of our excess entries into it.
671 */
672 error = xfs_da_grow_inode(state->args, &blkno);
673 if (error)
674 return error; /* GROT: dir is inconsistent */
675
676 error = xfs_da3_node_create(state->args, blkno, treelevel,
677 &newblk->bp, state->args->whichfork);
678 if (error)
679 return error; /* GROT: dir is inconsistent */
680 newblk->blkno = blkno;
681 newblk->magic = XFS_DA_NODE_MAGIC;
682 xfs_da3_node_rebalance(state, oldblk, newblk);
683 error = xfs_da3_blk_link(state, oldblk, newblk);
684 if (error)
685 return error;
686 *result = 1;
687 } else {
688 *result = 0;
689 }
690
691 /*
692 * Insert the new entry(s) into the correct block
693 * (updating last hashval in the process).
694 *
695 * xfs_da3_node_add() inserts BEFORE the given index,
696 * and as a result of using node_lookup_int() we always
697 * point to a valid entry (not after one), but a split
698 * operation always results in a new block whose hashvals
699 * FOLLOW the current block.
700 *
701 * If we had double-split op below us, then add the extra block too.
702 */
703 node = oldblk->bp->b_addr;
704 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
705 if (oldblk->index <= nodehdr.count) {
706 oldblk->index++;
707 xfs_da3_node_add(state, oldblk, addblk);
708 if (useextra) {
709 if (state->extraafter)
710 oldblk->index++;
711 xfs_da3_node_add(state, oldblk, &state->extrablk);
712 state->extravalid = 0;
713 }
714 } else {
715 newblk->index++;
716 xfs_da3_node_add(state, newblk, addblk);
717 if (useextra) {
718 if (state->extraafter)
719 newblk->index++;
720 xfs_da3_node_add(state, newblk, &state->extrablk);
721 state->extravalid = 0;
722 }
723 }
724
725 return 0;
726}
727
728/*
729 * Balance the btree elements between two intermediate nodes,
730 * usually one full and one empty.
731 *
732 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
733 */
734STATIC void
735xfs_da3_node_rebalance(
736 struct xfs_da_state *state,
737 struct xfs_da_state_blk *blk1,
738 struct xfs_da_state_blk *blk2)
739{
740 struct xfs_da_intnode *node1;
741 struct xfs_da_intnode *node2;
742 struct xfs_da_intnode *tmpnode;
743 struct xfs_da_node_entry *btree1;
744 struct xfs_da_node_entry *btree2;
745 struct xfs_da_node_entry *btree_s;
746 struct xfs_da_node_entry *btree_d;
747 struct xfs_da3_icnode_hdr nodehdr1;
748 struct xfs_da3_icnode_hdr nodehdr2;
749 struct xfs_trans *tp;
750 int count;
751 int tmp;
752 int swap = 0;
753 struct xfs_inode *dp = state->args->dp;
754
755 trace_xfs_da_node_rebalance(state->args);
756
757 node1 = blk1->bp->b_addr;
758 node2 = blk2->bp->b_addr;
759 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
760 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
761 btree1 = dp->d_ops->node_tree_p(node1);
762 btree2 = dp->d_ops->node_tree_p(node2);
763
764 /*
765 * Figure out how many entries need to move, and in which direction.
766 * Swap the nodes around if that makes it simpler.
767 */
768 if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
769 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
770 (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
771 be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
772 tmpnode = node1;
773 node1 = node2;
774 node2 = tmpnode;
775 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
776 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
777 btree1 = dp->d_ops->node_tree_p(node1);
778 btree2 = dp->d_ops->node_tree_p(node2);
779 swap = 1;
780 }
781
782 count = (nodehdr1.count - nodehdr2.count) / 2;
783 if (count == 0)
784 return;
785 tp = state->args->trans;
786 /*
787 * Two cases: high-to-low and low-to-high.
788 */
789 if (count > 0) {
790 /*
791 * Move elements in node2 up to make a hole.
792 */
793 tmp = nodehdr2.count;
794 if (tmp > 0) {
795 tmp *= (uint)sizeof(xfs_da_node_entry_t);
796 btree_s = &btree2[0];
797 btree_d = &btree2[count];
798 memmove(btree_d, btree_s, tmp);
799 }
800
801 /*
802 * Move the req'd B-tree elements from high in node1 to
803 * low in node2.
804 */
805 nodehdr2.count += count;
806 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
807 btree_s = &btree1[nodehdr1.count - count];
808 btree_d = &btree2[0];
809 memcpy(btree_d, btree_s, tmp);
810 nodehdr1.count -= count;
811 } else {
812 /*
813 * Move the req'd B-tree elements from low in node2 to
814 * high in node1.
815 */
816 count = -count;
817 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
818 btree_s = &btree2[0];
819 btree_d = &btree1[nodehdr1.count];
820 memcpy(btree_d, btree_s, tmp);
821 nodehdr1.count += count;
822
823 xfs_trans_log_buf(tp, blk1->bp,
824 XFS_DA_LOGRANGE(node1, btree_d, tmp));
825
826 /*
827 * Move elements in node2 down to fill the hole.
828 */
829 tmp = nodehdr2.count - count;
830 tmp *= (uint)sizeof(xfs_da_node_entry_t);
831 btree_s = &btree2[count];
832 btree_d = &btree2[0];
833 memmove(btree_d, btree_s, tmp);
834 nodehdr2.count -= count;
835 }
836
837 /*
838 * Log header of node 1 and all current bits of node 2.
839 */
840 dp->d_ops->node_hdr_to_disk(node1, &nodehdr1);
841 xfs_trans_log_buf(tp, blk1->bp,
842 XFS_DA_LOGRANGE(node1, &node1->hdr, dp->d_ops->node_hdr_size));
843
844 dp->d_ops->node_hdr_to_disk(node2, &nodehdr2);
845 xfs_trans_log_buf(tp, blk2->bp,
846 XFS_DA_LOGRANGE(node2, &node2->hdr,
847 dp->d_ops->node_hdr_size +
848 (sizeof(btree2[0]) * nodehdr2.count)));
849
850 /*
851 * Record the last hashval from each block for upward propagation.
852 * (note: don't use the swapped node pointers)
853 */
854 if (swap) {
855 node1 = blk1->bp->b_addr;
856 node2 = blk2->bp->b_addr;
857 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
858 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
859 btree1 = dp->d_ops->node_tree_p(node1);
860 btree2 = dp->d_ops->node_tree_p(node2);
861 }
862 blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
863 blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
864
865 /*
866 * Adjust the expected index for insertion.
867 */
868 if (blk1->index >= nodehdr1.count) {
869 blk2->index = blk1->index - nodehdr1.count;
870 blk1->index = nodehdr1.count + 1; /* make it invalid */
871 }
872}
873
874/*
875 * Add a new entry to an intermediate node.
876 */
877STATIC void
878xfs_da3_node_add(
879 struct xfs_da_state *state,
880 struct xfs_da_state_blk *oldblk,
881 struct xfs_da_state_blk *newblk)
882{
883 struct xfs_da_intnode *node;
884 struct xfs_da3_icnode_hdr nodehdr;
885 struct xfs_da_node_entry *btree;
886 int tmp;
887 struct xfs_inode *dp = state->args->dp;
888
889 trace_xfs_da_node_add(state->args);
890
891 node = oldblk->bp->b_addr;
892 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
893 btree = dp->d_ops->node_tree_p(node);
894
895 ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
896 ASSERT(newblk->blkno != 0);
897 if (state->args->whichfork == XFS_DATA_FORK)
898 ASSERT(newblk->blkno >= state->args->geo->leafblk &&
899 newblk->blkno < state->args->geo->freeblk);
900
901 /*
902 * We may need to make some room before we insert the new node.
903 */
904 tmp = 0;
905 if (oldblk->index < nodehdr.count) {
906 tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
907 memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
908 }
909 btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
910 btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
911 xfs_trans_log_buf(state->args->trans, oldblk->bp,
912 XFS_DA_LOGRANGE(node, &btree[oldblk->index],
913 tmp + sizeof(*btree)));
914
915 nodehdr.count += 1;
916 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
917 xfs_trans_log_buf(state->args->trans, oldblk->bp,
918 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
919
920 /*
921 * Copy the last hash value from the oldblk to propagate upwards.
922 */
923 oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
924}
925
926/*========================================================================
927 * Routines used for shrinking the Btree.
928 *========================================================================*/
929
930/*
931 * Deallocate an empty leaf node, remove it from its parent,
932 * possibly deallocating that block, etc...
933 */
934int
935xfs_da3_join(
936 struct xfs_da_state *state)
937{
938 struct xfs_da_state_blk *drop_blk;
939 struct xfs_da_state_blk *save_blk;
940 int action = 0;
941 int error;
942
943 trace_xfs_da_join(state->args);
944
945 drop_blk = &state->path.blk[ state->path.active-1 ];
946 save_blk = &state->altpath.blk[ state->path.active-1 ];
947 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
948 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
949 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
950
951 /*
952 * Walk back up the tree joining/deallocating as necessary.
953 * When we stop dropping blocks, break out.
954 */
955 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
956 state->path.active--) {
957 /*
958 * See if we can combine the block with a neighbor.
959 * (action == 0) => no options, just leave
960 * (action == 1) => coalesce, then unlink
961 * (action == 2) => block empty, unlink it
962 */
963 switch (drop_blk->magic) {
964 case XFS_ATTR_LEAF_MAGIC:
965 error = xfs_attr3_leaf_toosmall(state, &action);
966 if (error)
967 return error;
968 if (action == 0)
969 return 0;
970 xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
971 break;
972 case XFS_DIR2_LEAFN_MAGIC:
973 error = xfs_dir2_leafn_toosmall(state, &action);
974 if (error)
975 return error;
976 if (action == 0)
977 return 0;
978 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
979 break;
980 case XFS_DA_NODE_MAGIC:
981 /*
982 * Remove the offending node, fixup hashvals,
983 * check for a toosmall neighbor.
984 */
985 xfs_da3_node_remove(state, drop_blk);
986 xfs_da3_fixhashpath(state, &state->path);
987 error = xfs_da3_node_toosmall(state, &action);
988 if (error)
989 return error;
990 if (action == 0)
991 return 0;
992 xfs_da3_node_unbalance(state, drop_blk, save_blk);
993 break;
994 }
995 xfs_da3_fixhashpath(state, &state->altpath);
996 error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
997 xfs_da_state_kill_altpath(state);
998 if (error)
999 return error;
1000 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1001 drop_blk->bp);
1002 drop_blk->bp = NULL;
1003 if (error)
1004 return error;
1005 }
1006 /*
1007 * We joined all the way to the top. If it turns out that
1008 * we only have one entry in the root, make the child block
1009 * the new root.
1010 */
1011 xfs_da3_node_remove(state, drop_blk);
1012 xfs_da3_fixhashpath(state, &state->path);
1013 error = xfs_da3_root_join(state, &state->path.blk[0]);
1014 return error;
1015}
1016
1017#ifdef DEBUG
1018static void
1019xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1020{
1021 __be16 magic = blkinfo->magic;
1022
1023 if (level == 1) {
1024 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1025 magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1026 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1027 magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1028 } else {
1029 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1030 magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1031 }
1032 ASSERT(!blkinfo->forw);
1033 ASSERT(!blkinfo->back);
1034}
1035#else /* !DEBUG */
1036#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1037#endif /* !DEBUG */
1038
1039/*
1040 * We have only one entry in the root. Copy the only remaining child of
1041 * the old root to block 0 as the new root node.
1042 */
1043STATIC int
1044xfs_da3_root_join(
1045 struct xfs_da_state *state,
1046 struct xfs_da_state_blk *root_blk)
1047{
1048 struct xfs_da_intnode *oldroot;
1049 struct xfs_da_args *args;
1050 xfs_dablk_t child;
1051 struct xfs_buf *bp;
1052 struct xfs_da3_icnode_hdr oldroothdr;
1053 struct xfs_da_node_entry *btree;
1054 int error;
1055 struct xfs_inode *dp = state->args->dp;
1056
1057 trace_xfs_da_root_join(state->args);
1058
1059 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1060
1061 args = state->args;
1062 oldroot = root_blk->bp->b_addr;
1063 dp->d_ops->node_hdr_from_disk(&oldroothdr, oldroot);
1064 ASSERT(oldroothdr.forw == 0);
1065 ASSERT(oldroothdr.back == 0);
1066
1067 /*
1068 * If the root has more than one child, then don't do anything.
1069 */
1070 if (oldroothdr.count > 1)
1071 return 0;
1072
1073 /*
1074 * Read in the (only) child block, then copy those bytes into
1075 * the root block's buffer and free the original child block.
1076 */
1077 btree = dp->d_ops->node_tree_p(oldroot);
1078 child = be32_to_cpu(btree[0].before);
1079 ASSERT(child != 0);
1080 error = xfs_da3_node_read(args->trans, dp, child, -1, &bp,
1081 args->whichfork);
1082 if (error)
1083 return error;
1084 xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1085
1086 /*
1087 * This could be copying a leaf back into the root block in the case of
1088 * there only being a single leaf block left in the tree. Hence we have
1089 * to update the b_ops pointer as well to match the buffer type change
1090 * that could occur. For dir3 blocks we also need to update the block
1091 * number in the buffer header.
1092 */
1093 memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1094 root_blk->bp->b_ops = bp->b_ops;
1095 xfs_trans_buf_copy_type(root_blk->bp, bp);
1096 if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1097 struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1098 da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
1099 }
1100 xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1101 args->geo->blksize - 1);
1102 error = xfs_da_shrink_inode(args, child, bp);
1103 return error;
1104}
1105
1106/*
1107 * Check a node block and its neighbors to see if the block should be
1108 * collapsed into one or the other neighbor. Always keep the block
1109 * with the smaller block number.
1110 * If the current block is over 50% full, don't try to join it, return 0.
1111 * If the block is empty, fill in the state structure and return 2.
1112 * If it can be collapsed, fill in the state structure and return 1.
1113 * If nothing can be done, return 0.
1114 */
1115STATIC int
1116xfs_da3_node_toosmall(
1117 struct xfs_da_state *state,
1118 int *action)
1119{
1120 struct xfs_da_intnode *node;
1121 struct xfs_da_state_blk *blk;
1122 struct xfs_da_blkinfo *info;
1123 xfs_dablk_t blkno;
1124 struct xfs_buf *bp;
1125 struct xfs_da3_icnode_hdr nodehdr;
1126 int count;
1127 int forward;
1128 int error;
1129 int retval;
1130 int i;
1131 struct xfs_inode *dp = state->args->dp;
1132
1133 trace_xfs_da_node_toosmall(state->args);
1134
1135 /*
1136 * Check for the degenerate case of the block being over 50% full.
1137 * If so, it's not worth even looking to see if we might be able
1138 * to coalesce with a sibling.
1139 */
1140 blk = &state->path.blk[ state->path.active-1 ];
1141 info = blk->bp->b_addr;
1142 node = (xfs_da_intnode_t *)info;
1143 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1144 if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1145 *action = 0; /* blk over 50%, don't try to join */
1146 return 0; /* blk over 50%, don't try to join */
1147 }
1148
1149 /*
1150 * Check for the degenerate case of the block being empty.
1151 * If the block is empty, we'll simply delete it, no need to
1152 * coalesce it with a sibling block. We choose (arbitrarily)
1153 * to merge with the forward block unless it is NULL.
1154 */
1155 if (nodehdr.count == 0) {
1156 /*
1157 * Make altpath point to the block we want to keep and
1158 * path point to the block we want to drop (this one).
1159 */
1160 forward = (info->forw != 0);
1161 memcpy(&state->altpath, &state->path, sizeof(state->path));
1162 error = xfs_da3_path_shift(state, &state->altpath, forward,
1163 0, &retval);
1164 if (error)
1165 return error;
1166 if (retval) {
1167 *action = 0;
1168 } else {
1169 *action = 2;
1170 }
1171 return 0;
1172 }
1173
1174 /*
1175 * Examine each sibling block to see if we can coalesce with
1176 * at least 25% free space to spare. We need to figure out
1177 * whether to merge with the forward or the backward block.
1178 * We prefer coalescing with the lower numbered sibling so as
1179 * to shrink a directory over time.
1180 */
1181 count = state->args->geo->node_ents;
1182 count -= state->args->geo->node_ents >> 2;
1183 count -= nodehdr.count;
1184
1185 /* start with smaller blk num */
1186 forward = nodehdr.forw < nodehdr.back;
1187 for (i = 0; i < 2; forward = !forward, i++) {
1188 struct xfs_da3_icnode_hdr thdr;
1189 if (forward)
1190 blkno = nodehdr.forw;
1191 else
1192 blkno = nodehdr.back;
1193 if (blkno == 0)
1194 continue;
1195 error = xfs_da3_node_read(state->args->trans, dp,
1196 blkno, -1, &bp, state->args->whichfork);
1197 if (error)
1198 return error;
1199
1200 node = bp->b_addr;
1201 dp->d_ops->node_hdr_from_disk(&thdr, node);
1202 xfs_trans_brelse(state->args->trans, bp);
1203
1204 if (count - thdr.count >= 0)
1205 break; /* fits with at least 25% to spare */
1206 }
1207 if (i >= 2) {
1208 *action = 0;
1209 return 0;
1210 }
1211
1212 /*
1213 * Make altpath point to the block we want to keep (the lower
1214 * numbered block) and path point to the block we want to drop.
1215 */
1216 memcpy(&state->altpath, &state->path, sizeof(state->path));
1217 if (blkno < blk->blkno) {
1218 error = xfs_da3_path_shift(state, &state->altpath, forward,
1219 0, &retval);
1220 } else {
1221 error = xfs_da3_path_shift(state, &state->path, forward,
1222 0, &retval);
1223 }
1224 if (error)
1225 return error;
1226 if (retval) {
1227 *action = 0;
1228 return 0;
1229 }
1230 *action = 1;
1231 return 0;
1232}
1233
1234/*
1235 * Pick up the last hashvalue from an intermediate node.
1236 */
1237STATIC uint
1238xfs_da3_node_lasthash(
1239 struct xfs_inode *dp,
1240 struct xfs_buf *bp,
1241 int *count)
1242{
1243 struct xfs_da_intnode *node;
1244 struct xfs_da_node_entry *btree;
1245 struct xfs_da3_icnode_hdr nodehdr;
1246
1247 node = bp->b_addr;
1248 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1249 if (count)
1250 *count = nodehdr.count;
1251 if (!nodehdr.count)
1252 return 0;
1253 btree = dp->d_ops->node_tree_p(node);
1254 return be32_to_cpu(btree[nodehdr.count - 1].hashval);
1255}
1256
1257/*
1258 * Walk back up the tree adjusting hash values as necessary,
1259 * when we stop making changes, return.
1260 */
1261void
1262xfs_da3_fixhashpath(
1263 struct xfs_da_state *state,
1264 struct xfs_da_state_path *path)
1265{
1266 struct xfs_da_state_blk *blk;
1267 struct xfs_da_intnode *node;
1268 struct xfs_da_node_entry *btree;
1269 xfs_dahash_t lasthash=0;
1270 int level;
1271 int count;
1272 struct xfs_inode *dp = state->args->dp;
1273
1274 trace_xfs_da_fixhashpath(state->args);
1275
1276 level = path->active-1;
1277 blk = &path->blk[ level ];
1278 switch (blk->magic) {
1279 case XFS_ATTR_LEAF_MAGIC:
1280 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1281 if (count == 0)
1282 return;
1283 break;
1284 case XFS_DIR2_LEAFN_MAGIC:
1285 lasthash = xfs_dir2_leafn_lasthash(dp, blk->bp, &count);
1286 if (count == 0)
1287 return;
1288 break;
1289 case XFS_DA_NODE_MAGIC:
1290 lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1291 if (count == 0)
1292 return;
1293 break;
1294 }
1295 for (blk--, level--; level >= 0; blk--, level--) {
1296 struct xfs_da3_icnode_hdr nodehdr;
1297
1298 node = blk->bp->b_addr;
1299 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1300 btree = dp->d_ops->node_tree_p(node);
1301 if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1302 break;
1303 blk->hashval = lasthash;
1304 btree[blk->index].hashval = cpu_to_be32(lasthash);
1305 xfs_trans_log_buf(state->args->trans, blk->bp,
1306 XFS_DA_LOGRANGE(node, &btree[blk->index],
1307 sizeof(*btree)));
1308
1309 lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1310 }
1311}
1312
1313/*
1314 * Remove an entry from an intermediate node.
1315 */
1316STATIC void
1317xfs_da3_node_remove(
1318 struct xfs_da_state *state,
1319 struct xfs_da_state_blk *drop_blk)
1320{
1321 struct xfs_da_intnode *node;
1322 struct xfs_da3_icnode_hdr nodehdr;
1323 struct xfs_da_node_entry *btree;
1324 int index;
1325 int tmp;
1326 struct xfs_inode *dp = state->args->dp;
1327
1328 trace_xfs_da_node_remove(state->args);
1329
1330 node = drop_blk->bp->b_addr;
1331 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1332 ASSERT(drop_blk->index < nodehdr.count);
1333 ASSERT(drop_blk->index >= 0);
1334
1335 /*
1336 * Copy over the offending entry, or just zero it out.
1337 */
1338 index = drop_blk->index;
1339 btree = dp->d_ops->node_tree_p(node);
1340 if (index < nodehdr.count - 1) {
1341 tmp = nodehdr.count - index - 1;
1342 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1343 memmove(&btree[index], &btree[index + 1], tmp);
1344 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1345 XFS_DA_LOGRANGE(node, &btree[index], tmp));
1346 index = nodehdr.count - 1;
1347 }
1348 memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1349 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1350 XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1351 nodehdr.count -= 1;
1352 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
1353 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1354 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
1355
1356 /*
1357 * Copy the last hash value from the block to propagate upwards.
1358 */
1359 drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1360}
1361
1362/*
1363 * Unbalance the elements between two intermediate nodes,
1364 * move all Btree elements from one node into another.
1365 */
1366STATIC void
1367xfs_da3_node_unbalance(
1368 struct xfs_da_state *state,
1369 struct xfs_da_state_blk *drop_blk,
1370 struct xfs_da_state_blk *save_blk)
1371{
1372 struct xfs_da_intnode *drop_node;
1373 struct xfs_da_intnode *save_node;
1374 struct xfs_da_node_entry *drop_btree;
1375 struct xfs_da_node_entry *save_btree;
1376 struct xfs_da3_icnode_hdr drop_hdr;
1377 struct xfs_da3_icnode_hdr save_hdr;
1378 struct xfs_trans *tp;
1379 int sindex;
1380 int tmp;
1381 struct xfs_inode *dp = state->args->dp;
1382
1383 trace_xfs_da_node_unbalance(state->args);
1384
1385 drop_node = drop_blk->bp->b_addr;
1386 save_node = save_blk->bp->b_addr;
1387 dp->d_ops->node_hdr_from_disk(&drop_hdr, drop_node);
1388 dp->d_ops->node_hdr_from_disk(&save_hdr, save_node);
1389 drop_btree = dp->d_ops->node_tree_p(drop_node);
1390 save_btree = dp->d_ops->node_tree_p(save_node);
1391 tp = state->args->trans;
1392
1393 /*
1394 * If the dying block has lower hashvals, then move all the
1395 * elements in the remaining block up to make a hole.
1396 */
1397 if ((be32_to_cpu(drop_btree[0].hashval) <
1398 be32_to_cpu(save_btree[0].hashval)) ||
1399 (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1400 be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1401 /* XXX: check this - is memmove dst correct? */
1402 tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1403 memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1404
1405 sindex = 0;
1406 xfs_trans_log_buf(tp, save_blk->bp,
1407 XFS_DA_LOGRANGE(save_node, &save_btree[0],
1408 (save_hdr.count + drop_hdr.count) *
1409 sizeof(xfs_da_node_entry_t)));
1410 } else {
1411 sindex = save_hdr.count;
1412 xfs_trans_log_buf(tp, save_blk->bp,
1413 XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1414 drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1415 }
1416
1417 /*
1418 * Move all the B-tree elements from drop_blk to save_blk.
1419 */
1420 tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1421 memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1422 save_hdr.count += drop_hdr.count;
1423
1424 dp->d_ops->node_hdr_to_disk(save_node, &save_hdr);
1425 xfs_trans_log_buf(tp, save_blk->bp,
1426 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1427 dp->d_ops->node_hdr_size));
1428
1429 /*
1430 * Save the last hashval in the remaining block for upward propagation.
1431 */
1432 save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1433}
1434
1435/*========================================================================
1436 * Routines used for finding things in the Btree.
1437 *========================================================================*/
1438
1439/*
1440 * Walk down the Btree looking for a particular filename, filling
1441 * in the state structure as we go.
1442 *
1443 * We will set the state structure to point to each of the elements
1444 * in each of the nodes where either the hashval is or should be.
1445 *
1446 * We support duplicate hashval's so for each entry in the current
1447 * node that could contain the desired hashval, descend. This is a
1448 * pruned depth-first tree search.
1449 */
1450int /* error */
1451xfs_da3_node_lookup_int(
1452 struct xfs_da_state *state,
1453 int *result)
1454{
1455 struct xfs_da_state_blk *blk;
1456 struct xfs_da_blkinfo *curr;
1457 struct xfs_da_intnode *node;
1458 struct xfs_da_node_entry *btree;
1459 struct xfs_da3_icnode_hdr nodehdr;
1460 struct xfs_da_args *args;
1461 xfs_dablk_t blkno;
1462 xfs_dahash_t hashval;
1463 xfs_dahash_t btreehashval;
1464 int probe;
1465 int span;
1466 int max;
1467 int error;
1468 int retval;
1469 struct xfs_inode *dp = state->args->dp;
1470
1471 args = state->args;
1472
1473 /*
1474 * Descend thru the B-tree searching each level for the right
1475 * node to use, until the right hashval is found.
1476 */
1477 blkno = (args->whichfork == XFS_DATA_FORK)? args->geo->leafblk : 0;
1478 for (blk = &state->path.blk[0], state->path.active = 1;
1479 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1480 blk++, state->path.active++) {
1481 /*
1482 * Read the next node down in the tree.
1483 */
1484 blk->blkno = blkno;
1485 error = xfs_da3_node_read(args->trans, args->dp, blkno,
1486 -1, &blk->bp, args->whichfork);
1487 if (error) {
1488 blk->blkno = 0;
1489 state->path.active--;
1490 return error;
1491 }
1492 curr = blk->bp->b_addr;
1493 blk->magic = be16_to_cpu(curr->magic);
1494
1495 if (blk->magic == XFS_ATTR_LEAF_MAGIC ||
1496 blk->magic == XFS_ATTR3_LEAF_MAGIC) {
1497 blk->magic = XFS_ATTR_LEAF_MAGIC;
1498 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1499 break;
1500 }
1501
1502 if (blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1503 blk->magic == XFS_DIR3_LEAFN_MAGIC) {
1504 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1505 blk->hashval = xfs_dir2_leafn_lasthash(args->dp,
1506 blk->bp, NULL);
1507 break;
1508 }
1509
1510 blk->magic = XFS_DA_NODE_MAGIC;
1511
1512
1513 /*
1514 * Search an intermediate node for a match.
1515 */
1516 node = blk->bp->b_addr;
1517 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1518 btree = dp->d_ops->node_tree_p(node);
1519
1520 max = nodehdr.count;
1521 blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1522
1523 /*
1524 * Binary search. (note: small blocks will skip loop)
1525 */
1526 probe = span = max / 2;
1527 hashval = args->hashval;
1528 while (span > 4) {
1529 span /= 2;
1530 btreehashval = be32_to_cpu(btree[probe].hashval);
1531 if (btreehashval < hashval)
1532 probe += span;
1533 else if (btreehashval > hashval)
1534 probe -= span;
1535 else
1536 break;
1537 }
1538 ASSERT((probe >= 0) && (probe < max));
1539 ASSERT((span <= 4) ||
1540 (be32_to_cpu(btree[probe].hashval) == hashval));
1541
1542 /*
1543 * Since we may have duplicate hashval's, find the first
1544 * matching hashval in the node.
1545 */
1546 while (probe > 0 &&
1547 be32_to_cpu(btree[probe].hashval) >= hashval) {
1548 probe--;
1549 }
1550 while (probe < max &&
1551 be32_to_cpu(btree[probe].hashval) < hashval) {
1552 probe++;
1553 }
1554
1555 /*
1556 * Pick the right block to descend on.
1557 */
1558 if (probe == max) {
1559 blk->index = max - 1;
1560 blkno = be32_to_cpu(btree[max - 1].before);
1561 } else {
1562 blk->index = probe;
1563 blkno = be32_to_cpu(btree[probe].before);
1564 }
1565 }
1566
1567 /*
1568 * A leaf block that ends in the hashval that we are interested in
1569 * (final hashval == search hashval) means that the next block may
1570 * contain more entries with the same hashval, shift upward to the
1571 * next leaf and keep searching.
1572 */
1573 for (;;) {
1574 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1575 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1576 &blk->index, state);
1577 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1578 retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1579 blk->index = args->index;
1580 args->blkno = blk->blkno;
1581 } else {
1582 ASSERT(0);
1583 return -EFSCORRUPTED;
1584 }
1585 if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1586 (blk->hashval == args->hashval)) {
1587 error = xfs_da3_path_shift(state, &state->path, 1, 1,
1588 &retval);
1589 if (error)
1590 return error;
1591 if (retval == 0) {
1592 continue;
1593 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1594 /* path_shift() gives ENOENT */
1595 retval = -ENOATTR;
1596 }
1597 }
1598 break;
1599 }
1600 *result = retval;
1601 return 0;
1602}
1603
1604/*========================================================================
1605 * Utility routines.
1606 *========================================================================*/
1607
1608/*
1609 * Compare two intermediate nodes for "order".
1610 */
1611STATIC int
1612xfs_da3_node_order(
1613 struct xfs_inode *dp,
1614 struct xfs_buf *node1_bp,
1615 struct xfs_buf *node2_bp)
1616{
1617 struct xfs_da_intnode *node1;
1618 struct xfs_da_intnode *node2;
1619 struct xfs_da_node_entry *btree1;
1620 struct xfs_da_node_entry *btree2;
1621 struct xfs_da3_icnode_hdr node1hdr;
1622 struct xfs_da3_icnode_hdr node2hdr;
1623
1624 node1 = node1_bp->b_addr;
1625 node2 = node2_bp->b_addr;
1626 dp->d_ops->node_hdr_from_disk(&node1hdr, node1);
1627 dp->d_ops->node_hdr_from_disk(&node2hdr, node2);
1628 btree1 = dp->d_ops->node_tree_p(node1);
1629 btree2 = dp->d_ops->node_tree_p(node2);
1630
1631 if (node1hdr.count > 0 && node2hdr.count > 0 &&
1632 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1633 (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1634 be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1635 return 1;
1636 }
1637 return 0;
1638}
1639
1640/*
1641 * Link a new block into a doubly linked list of blocks (of whatever type).
1642 */
1643int /* error */
1644xfs_da3_blk_link(
1645 struct xfs_da_state *state,
1646 struct xfs_da_state_blk *old_blk,
1647 struct xfs_da_state_blk *new_blk)
1648{
1649 struct xfs_da_blkinfo *old_info;
1650 struct xfs_da_blkinfo *new_info;
1651 struct xfs_da_blkinfo *tmp_info;
1652 struct xfs_da_args *args;
1653 struct xfs_buf *bp;
1654 int before = 0;
1655 int error;
1656 struct xfs_inode *dp = state->args->dp;
1657
1658 /*
1659 * Set up environment.
1660 */
1661 args = state->args;
1662 ASSERT(args != NULL);
1663 old_info = old_blk->bp->b_addr;
1664 new_info = new_blk->bp->b_addr;
1665 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1666 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1667 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1668
1669 switch (old_blk->magic) {
1670 case XFS_ATTR_LEAF_MAGIC:
1671 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1672 break;
1673 case XFS_DIR2_LEAFN_MAGIC:
1674 before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1675 break;
1676 case XFS_DA_NODE_MAGIC:
1677 before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1678 break;
1679 }
1680
1681 /*
1682 * Link blocks in appropriate order.
1683 */
1684 if (before) {
1685 /*
1686 * Link new block in before existing block.
1687 */
1688 trace_xfs_da_link_before(args);
1689 new_info->forw = cpu_to_be32(old_blk->blkno);
1690 new_info->back = old_info->back;
1691 if (old_info->back) {
1692 error = xfs_da3_node_read(args->trans, dp,
1693 be32_to_cpu(old_info->back),
1694 -1, &bp, args->whichfork);
1695 if (error)
1696 return error;
1697 ASSERT(bp != NULL);
1698 tmp_info = bp->b_addr;
1699 ASSERT(tmp_info->magic == old_info->magic);
1700 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1701 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1702 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1703 }
1704 old_info->back = cpu_to_be32(new_blk->blkno);
1705 } else {
1706 /*
1707 * Link new block in after existing block.
1708 */
1709 trace_xfs_da_link_after(args);
1710 new_info->forw = old_info->forw;
1711 new_info->back = cpu_to_be32(old_blk->blkno);
1712 if (old_info->forw) {
1713 error = xfs_da3_node_read(args->trans, dp,
1714 be32_to_cpu(old_info->forw),
1715 -1, &bp, args->whichfork);
1716 if (error)
1717 return error;
1718 ASSERT(bp != NULL);
1719 tmp_info = bp->b_addr;
1720 ASSERT(tmp_info->magic == old_info->magic);
1721 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1722 tmp_info->back = cpu_to_be32(new_blk->blkno);
1723 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1724 }
1725 old_info->forw = cpu_to_be32(new_blk->blkno);
1726 }
1727
1728 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1729 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1730 return 0;
1731}
1732
1733/*
1734 * Unlink a block from a doubly linked list of blocks.
1735 */
1736STATIC int /* error */
1737xfs_da3_blk_unlink(
1738 struct xfs_da_state *state,
1739 struct xfs_da_state_blk *drop_blk,
1740 struct xfs_da_state_blk *save_blk)
1741{
1742 struct xfs_da_blkinfo *drop_info;
1743 struct xfs_da_blkinfo *save_info;
1744 struct xfs_da_blkinfo *tmp_info;
1745 struct xfs_da_args *args;
1746 struct xfs_buf *bp;
1747 int error;
1748
1749 /*
1750 * Set up environment.
1751 */
1752 args = state->args;
1753 ASSERT(args != NULL);
1754 save_info = save_blk->bp->b_addr;
1755 drop_info = drop_blk->bp->b_addr;
1756 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1757 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1758 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1759 ASSERT(save_blk->magic == drop_blk->magic);
1760 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1761 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1762 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1763 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1764
1765 /*
1766 * Unlink the leaf block from the doubly linked chain of leaves.
1767 */
1768 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1769 trace_xfs_da_unlink_back(args);
1770 save_info->back = drop_info->back;
1771 if (drop_info->back) {
1772 error = xfs_da3_node_read(args->trans, args->dp,
1773 be32_to_cpu(drop_info->back),
1774 -1, &bp, args->whichfork);
1775 if (error)
1776 return error;
1777 ASSERT(bp != NULL);
1778 tmp_info = bp->b_addr;
1779 ASSERT(tmp_info->magic == save_info->magic);
1780 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1781 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1782 xfs_trans_log_buf(args->trans, bp, 0,
1783 sizeof(*tmp_info) - 1);
1784 }
1785 } else {
1786 trace_xfs_da_unlink_forward(args);
1787 save_info->forw = drop_info->forw;
1788 if (drop_info->forw) {
1789 error = xfs_da3_node_read(args->trans, args->dp,
1790 be32_to_cpu(drop_info->forw),
1791 -1, &bp, args->whichfork);
1792 if (error)
1793 return error;
1794 ASSERT(bp != NULL);
1795 tmp_info = bp->b_addr;
1796 ASSERT(tmp_info->magic == save_info->magic);
1797 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1798 tmp_info->back = cpu_to_be32(save_blk->blkno);
1799 xfs_trans_log_buf(args->trans, bp, 0,
1800 sizeof(*tmp_info) - 1);
1801 }
1802 }
1803
1804 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1805 return 0;
1806}
1807
1808/*
1809 * Move a path "forward" or "!forward" one block at the current level.
1810 *
1811 * This routine will adjust a "path" to point to the next block
1812 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1813 * Btree, including updating pointers to the intermediate nodes between
1814 * the new bottom and the root.
1815 */
1816int /* error */
1817xfs_da3_path_shift(
1818 struct xfs_da_state *state,
1819 struct xfs_da_state_path *path,
1820 int forward,
1821 int release,
1822 int *result)
1823{
1824 struct xfs_da_state_blk *blk;
1825 struct xfs_da_blkinfo *info;
1826 struct xfs_da_intnode *node;
1827 struct xfs_da_args *args;
1828 struct xfs_da_node_entry *btree;
1829 struct xfs_da3_icnode_hdr nodehdr;
1830 struct xfs_buf *bp;
1831 xfs_dablk_t blkno = 0;
1832 int level;
1833 int error;
1834 struct xfs_inode *dp = state->args->dp;
1835
1836 trace_xfs_da_path_shift(state->args);
1837
1838 /*
1839 * Roll up the Btree looking for the first block where our
1840 * current index is not at the edge of the block. Note that
1841 * we skip the bottom layer because we want the sibling block.
1842 */
1843 args = state->args;
1844 ASSERT(args != NULL);
1845 ASSERT(path != NULL);
1846 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1847 level = (path->active-1) - 1; /* skip bottom layer in path */
1848 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1849 node = blk->bp->b_addr;
1850 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1851 btree = dp->d_ops->node_tree_p(node);
1852
1853 if (forward && (blk->index < nodehdr.count - 1)) {
1854 blk->index++;
1855 blkno = be32_to_cpu(btree[blk->index].before);
1856 break;
1857 } else if (!forward && (blk->index > 0)) {
1858 blk->index--;
1859 blkno = be32_to_cpu(btree[blk->index].before);
1860 break;
1861 }
1862 }
1863 if (level < 0) {
1864 *result = -ENOENT; /* we're out of our tree */
1865 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1866 return 0;
1867 }
1868
1869 /*
1870 * Roll down the edge of the subtree until we reach the
1871 * same depth we were at originally.
1872 */
1873 for (blk++, level++; level < path->active; blk++, level++) {
1874 /*
1875 * Read the next child block into a local buffer.
1876 */
1877 error = xfs_da3_node_read(args->trans, dp, blkno, -1, &bp,
1878 args->whichfork);
1879 if (error)
1880 return error;
1881
1882 /*
1883 * Release the old block (if it's dirty, the trans doesn't
1884 * actually let go) and swap the local buffer into the path
1885 * structure. This ensures failure of the above read doesn't set
1886 * a NULL buffer in an active slot in the path.
1887 */
1888 if (release)
1889 xfs_trans_brelse(args->trans, blk->bp);
1890 blk->blkno = blkno;
1891 blk->bp = bp;
1892
1893 info = blk->bp->b_addr;
1894 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1895 info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
1896 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1897 info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1898 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1899 info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1900
1901
1902 /*
1903 * Note: we flatten the magic number to a single type so we
1904 * don't have to compare against crc/non-crc types elsewhere.
1905 */
1906 switch (be16_to_cpu(info->magic)) {
1907 case XFS_DA_NODE_MAGIC:
1908 case XFS_DA3_NODE_MAGIC:
1909 blk->magic = XFS_DA_NODE_MAGIC;
1910 node = (xfs_da_intnode_t *)info;
1911 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1912 btree = dp->d_ops->node_tree_p(node);
1913 blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1914 if (forward)
1915 blk->index = 0;
1916 else
1917 blk->index = nodehdr.count - 1;
1918 blkno = be32_to_cpu(btree[blk->index].before);
1919 break;
1920 case XFS_ATTR_LEAF_MAGIC:
1921 case XFS_ATTR3_LEAF_MAGIC:
1922 blk->magic = XFS_ATTR_LEAF_MAGIC;
1923 ASSERT(level == path->active-1);
1924 blk->index = 0;
1925 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1926 break;
1927 case XFS_DIR2_LEAFN_MAGIC:
1928 case XFS_DIR3_LEAFN_MAGIC:
1929 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1930 ASSERT(level == path->active-1);
1931 blk->index = 0;
1932 blk->hashval = xfs_dir2_leafn_lasthash(args->dp,
1933 blk->bp, NULL);
1934 break;
1935 default:
1936 ASSERT(0);
1937 break;
1938 }
1939 }
1940 *result = 0;
1941 return 0;
1942}
1943
1944
1945/*========================================================================
1946 * Utility routines.
1947 *========================================================================*/
1948
1949/*
1950 * Implement a simple hash on a character string.
1951 * Rotate the hash value by 7 bits, then XOR each character in.
1952 * This is implemented with some source-level loop unrolling.
1953 */
1954xfs_dahash_t
1955xfs_da_hashname(const __uint8_t *name, int namelen)
1956{
1957 xfs_dahash_t hash;
1958
1959 /*
1960 * Do four characters at a time as long as we can.
1961 */
1962 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1963 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1964 (name[3] << 0) ^ rol32(hash, 7 * 4);
1965
1966 /*
1967 * Now do the rest of the characters.
1968 */
1969 switch (namelen) {
1970 case 3:
1971 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1972 rol32(hash, 7 * 3);
1973 case 2:
1974 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1975 case 1:
1976 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1977 default: /* case 0: */
1978 return hash;
1979 }
1980}
1981
1982enum xfs_dacmp
1983xfs_da_compname(
1984 struct xfs_da_args *args,
1985 const unsigned char *name,
1986 int len)
1987{
1988 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1989 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1990}
1991
1992static xfs_dahash_t
1993xfs_default_hashname(
1994 struct xfs_name *name)
1995{
1996 return xfs_da_hashname(name->name, name->len);
1997}
1998
1999const struct xfs_nameops xfs_default_nameops = {
2000 .hashname = xfs_default_hashname,
2001 .compname = xfs_da_compname
2002};
2003
2004int
2005xfs_da_grow_inode_int(
2006 struct xfs_da_args *args,
2007 xfs_fileoff_t *bno,
2008 int count)
2009{
2010 struct xfs_trans *tp = args->trans;
2011 struct xfs_inode *dp = args->dp;
2012 int w = args->whichfork;
2013 xfs_rfsblock_t nblks = dp->i_d.di_nblocks;
2014 struct xfs_bmbt_irec map, *mapp;
2015 int nmap, error, got, i, mapi;
2016
2017 /*
2018 * Find a spot in the file space to put the new block.
2019 */
2020 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2021 if (error)
2022 return error;
2023
2024 /*
2025 * Try mapping it in one filesystem block.
2026 */
2027 nmap = 1;
2028 ASSERT(args->firstblock != NULL);
2029 error = xfs_bmapi_write(tp, dp, *bno, count,
2030 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2031 args->firstblock, args->total, &map, &nmap,
2032 args->dfops);
2033 if (error)
2034 return error;
2035
2036 ASSERT(nmap <= 1);
2037 if (nmap == 1) {
2038 mapp = ↦
2039 mapi = 1;
2040 } else if (nmap == 0 && count > 1) {
2041 xfs_fileoff_t b;
2042 int c;
2043
2044 /*
2045 * If we didn't get it and the block might work if fragmented,
2046 * try without the CONTIG flag. Loop until we get it all.
2047 */
2048 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
2049 for (b = *bno, mapi = 0; b < *bno + count; ) {
2050 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
2051 c = (int)(*bno + count - b);
2052 error = xfs_bmapi_write(tp, dp, b, c,
2053 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2054 args->firstblock, args->total,
2055 &mapp[mapi], &nmap, args->dfops);
2056 if (error)
2057 goto out_free_map;
2058 if (nmap < 1)
2059 break;
2060 mapi += nmap;
2061 b = mapp[mapi - 1].br_startoff +
2062 mapp[mapi - 1].br_blockcount;
2063 }
2064 } else {
2065 mapi = 0;
2066 mapp = NULL;
2067 }
2068
2069 /*
2070 * Count the blocks we got, make sure it matches the total.
2071 */
2072 for (i = 0, got = 0; i < mapi; i++)
2073 got += mapp[i].br_blockcount;
2074 if (got != count || mapp[0].br_startoff != *bno ||
2075 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2076 *bno + count) {
2077 error = -ENOSPC;
2078 goto out_free_map;
2079 }
2080
2081 /* account for newly allocated blocks in reserved blocks total */
2082 args->total -= dp->i_d.di_nblocks - nblks;
2083
2084out_free_map:
2085 if (mapp != &map)
2086 kmem_free(mapp);
2087 return error;
2088}
2089
2090/*
2091 * Add a block to the btree ahead of the file.
2092 * Return the new block number to the caller.
2093 */
2094int
2095xfs_da_grow_inode(
2096 struct xfs_da_args *args,
2097 xfs_dablk_t *new_blkno)
2098{
2099 xfs_fileoff_t bno;
2100 int error;
2101
2102 trace_xfs_da_grow_inode(args);
2103
2104 bno = args->geo->leafblk;
2105 error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2106 if (!error)
2107 *new_blkno = (xfs_dablk_t)bno;
2108 return error;
2109}
2110
2111/*
2112 * Ick. We need to always be able to remove a btree block, even
2113 * if there's no space reservation because the filesystem is full.
2114 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2115 * It swaps the target block with the last block in the file. The
2116 * last block in the file can always be removed since it can't cause
2117 * a bmap btree split to do that.
2118 */
2119STATIC int
2120xfs_da3_swap_lastblock(
2121 struct xfs_da_args *args,
2122 xfs_dablk_t *dead_blknop,
2123 struct xfs_buf **dead_bufp)
2124{
2125 struct xfs_da_blkinfo *dead_info;
2126 struct xfs_da_blkinfo *sib_info;
2127 struct xfs_da_intnode *par_node;
2128 struct xfs_da_intnode *dead_node;
2129 struct xfs_dir2_leaf *dead_leaf2;
2130 struct xfs_da_node_entry *btree;
2131 struct xfs_da3_icnode_hdr par_hdr;
2132 struct xfs_inode *dp;
2133 struct xfs_trans *tp;
2134 struct xfs_mount *mp;
2135 struct xfs_buf *dead_buf;
2136 struct xfs_buf *last_buf;
2137 struct xfs_buf *sib_buf;
2138 struct xfs_buf *par_buf;
2139 xfs_dahash_t dead_hash;
2140 xfs_fileoff_t lastoff;
2141 xfs_dablk_t dead_blkno;
2142 xfs_dablk_t last_blkno;
2143 xfs_dablk_t sib_blkno;
2144 xfs_dablk_t par_blkno;
2145 int error;
2146 int w;
2147 int entno;
2148 int level;
2149 int dead_level;
2150
2151 trace_xfs_da_swap_lastblock(args);
2152
2153 dead_buf = *dead_bufp;
2154 dead_blkno = *dead_blknop;
2155 tp = args->trans;
2156 dp = args->dp;
2157 w = args->whichfork;
2158 ASSERT(w == XFS_DATA_FORK);
2159 mp = dp->i_mount;
2160 lastoff = args->geo->freeblk;
2161 error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2162 if (error)
2163 return error;
2164 if (unlikely(lastoff == 0)) {
2165 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
2166 mp);
2167 return -EFSCORRUPTED;
2168 }
2169 /*
2170 * Read the last block in the btree space.
2171 */
2172 last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2173 error = xfs_da3_node_read(tp, dp, last_blkno, -1, &last_buf, w);
2174 if (error)
2175 return error;
2176 /*
2177 * Copy the last block into the dead buffer and log it.
2178 */
2179 memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2180 xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2181 dead_info = dead_buf->b_addr;
2182 /*
2183 * Get values from the moved block.
2184 */
2185 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2186 dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2187 struct xfs_dir3_icleaf_hdr leafhdr;
2188 struct xfs_dir2_leaf_entry *ents;
2189
2190 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2191 dp->d_ops->leaf_hdr_from_disk(&leafhdr, dead_leaf2);
2192 ents = dp->d_ops->leaf_ents_p(dead_leaf2);
2193 dead_level = 0;
2194 dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2195 } else {
2196 struct xfs_da3_icnode_hdr deadhdr;
2197
2198 dead_node = (xfs_da_intnode_t *)dead_info;
2199 dp->d_ops->node_hdr_from_disk(&deadhdr, dead_node);
2200 btree = dp->d_ops->node_tree_p(dead_node);
2201 dead_level = deadhdr.level;
2202 dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2203 }
2204 sib_buf = par_buf = NULL;
2205 /*
2206 * If the moved block has a left sibling, fix up the pointers.
2207 */
2208 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2209 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2210 if (error)
2211 goto done;
2212 sib_info = sib_buf->b_addr;
2213 if (unlikely(
2214 be32_to_cpu(sib_info->forw) != last_blkno ||
2215 sib_info->magic != dead_info->magic)) {
2216 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
2217 XFS_ERRLEVEL_LOW, mp);
2218 error = -EFSCORRUPTED;
2219 goto done;
2220 }
2221 sib_info->forw = cpu_to_be32(dead_blkno);
2222 xfs_trans_log_buf(tp, sib_buf,
2223 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2224 sizeof(sib_info->forw)));
2225 sib_buf = NULL;
2226 }
2227 /*
2228 * If the moved block has a right sibling, fix up the pointers.
2229 */
2230 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2231 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2232 if (error)
2233 goto done;
2234 sib_info = sib_buf->b_addr;
2235 if (unlikely(
2236 be32_to_cpu(sib_info->back) != last_blkno ||
2237 sib_info->magic != dead_info->magic)) {
2238 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
2239 XFS_ERRLEVEL_LOW, mp);
2240 error = -EFSCORRUPTED;
2241 goto done;
2242 }
2243 sib_info->back = cpu_to_be32(dead_blkno);
2244 xfs_trans_log_buf(tp, sib_buf,
2245 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2246 sizeof(sib_info->back)));
2247 sib_buf = NULL;
2248 }
2249 par_blkno = args->geo->leafblk;
2250 level = -1;
2251 /*
2252 * Walk down the tree looking for the parent of the moved block.
2253 */
2254 for (;;) {
2255 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2256 if (error)
2257 goto done;
2258 par_node = par_buf->b_addr;
2259 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2260 if (level >= 0 && level != par_hdr.level + 1) {
2261 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
2262 XFS_ERRLEVEL_LOW, mp);
2263 error = -EFSCORRUPTED;
2264 goto done;
2265 }
2266 level = par_hdr.level;
2267 btree = dp->d_ops->node_tree_p(par_node);
2268 for (entno = 0;
2269 entno < par_hdr.count &&
2270 be32_to_cpu(btree[entno].hashval) < dead_hash;
2271 entno++)
2272 continue;
2273 if (entno == par_hdr.count) {
2274 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
2275 XFS_ERRLEVEL_LOW, mp);
2276 error = -EFSCORRUPTED;
2277 goto done;
2278 }
2279 par_blkno = be32_to_cpu(btree[entno].before);
2280 if (level == dead_level + 1)
2281 break;
2282 xfs_trans_brelse(tp, par_buf);
2283 par_buf = NULL;
2284 }
2285 /*
2286 * We're in the right parent block.
2287 * Look for the right entry.
2288 */
2289 for (;;) {
2290 for (;
2291 entno < par_hdr.count &&
2292 be32_to_cpu(btree[entno].before) != last_blkno;
2293 entno++)
2294 continue;
2295 if (entno < par_hdr.count)
2296 break;
2297 par_blkno = par_hdr.forw;
2298 xfs_trans_brelse(tp, par_buf);
2299 par_buf = NULL;
2300 if (unlikely(par_blkno == 0)) {
2301 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
2302 XFS_ERRLEVEL_LOW, mp);
2303 error = -EFSCORRUPTED;
2304 goto done;
2305 }
2306 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2307 if (error)
2308 goto done;
2309 par_node = par_buf->b_addr;
2310 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2311 if (par_hdr.level != level) {
2312 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
2313 XFS_ERRLEVEL_LOW, mp);
2314 error = -EFSCORRUPTED;
2315 goto done;
2316 }
2317 btree = dp->d_ops->node_tree_p(par_node);
2318 entno = 0;
2319 }
2320 /*
2321 * Update the parent entry pointing to the moved block.
2322 */
2323 btree[entno].before = cpu_to_be32(dead_blkno);
2324 xfs_trans_log_buf(tp, par_buf,
2325 XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2326 sizeof(btree[entno].before)));
2327 *dead_blknop = last_blkno;
2328 *dead_bufp = last_buf;
2329 return 0;
2330done:
2331 if (par_buf)
2332 xfs_trans_brelse(tp, par_buf);
2333 if (sib_buf)
2334 xfs_trans_brelse(tp, sib_buf);
2335 xfs_trans_brelse(tp, last_buf);
2336 return error;
2337}
2338
2339/*
2340 * Remove a btree block from a directory or attribute.
2341 */
2342int
2343xfs_da_shrink_inode(
2344 xfs_da_args_t *args,
2345 xfs_dablk_t dead_blkno,
2346 struct xfs_buf *dead_buf)
2347{
2348 xfs_inode_t *dp;
2349 int done, error, w, count;
2350 xfs_trans_t *tp;
2351
2352 trace_xfs_da_shrink_inode(args);
2353
2354 dp = args->dp;
2355 w = args->whichfork;
2356 tp = args->trans;
2357 count = args->geo->fsbcount;
2358 for (;;) {
2359 /*
2360 * Remove extents. If we get ENOSPC for a dir we have to move
2361 * the last block to the place we want to kill.
2362 */
2363 error = xfs_bunmapi(tp, dp, dead_blkno, count,
2364 xfs_bmapi_aflag(w), 0, args->firstblock,
2365 args->dfops, &done);
2366 if (error == -ENOSPC) {
2367 if (w != XFS_DATA_FORK)
2368 break;
2369 error = xfs_da3_swap_lastblock(args, &dead_blkno,
2370 &dead_buf);
2371 if (error)
2372 break;
2373 } else {
2374 break;
2375 }
2376 }
2377 xfs_trans_binval(tp, dead_buf);
2378 return error;
2379}
2380
2381/*
2382 * See if the mapping(s) for this btree block are valid, i.e.
2383 * don't contain holes, are logically contiguous, and cover the whole range.
2384 */
2385STATIC int
2386xfs_da_map_covers_blocks(
2387 int nmap,
2388 xfs_bmbt_irec_t *mapp,
2389 xfs_dablk_t bno,
2390 int count)
2391{
2392 int i;
2393 xfs_fileoff_t off;
2394
2395 for (i = 0, off = bno; i < nmap; i++) {
2396 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2397 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2398 return 0;
2399 }
2400 if (off != mapp[i].br_startoff) {
2401 return 0;
2402 }
2403 off += mapp[i].br_blockcount;
2404 }
2405 return off == bno + count;
2406}
2407
2408/*
2409 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
2410 *
2411 * For the single map case, it is assumed that the caller has provided a pointer
2412 * to a valid xfs_buf_map. For the multiple map case, this function will
2413 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
2414 * map pointer with the allocated map.
2415 */
2416static int
2417xfs_buf_map_from_irec(
2418 struct xfs_mount *mp,
2419 struct xfs_buf_map **mapp,
2420 int *nmaps,
2421 struct xfs_bmbt_irec *irecs,
2422 int nirecs)
2423{
2424 struct xfs_buf_map *map;
2425 int i;
2426
2427 ASSERT(*nmaps == 1);
2428 ASSERT(nirecs >= 1);
2429
2430 if (nirecs > 1) {
2431 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map),
2432 KM_SLEEP | KM_NOFS);
2433 if (!map)
2434 return -ENOMEM;
2435 *mapp = map;
2436 }
2437
2438 *nmaps = nirecs;
2439 map = *mapp;
2440 for (i = 0; i < *nmaps; i++) {
2441 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
2442 irecs[i].br_startblock != HOLESTARTBLOCK);
2443 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2444 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2445 }
2446 return 0;
2447}
2448
2449/*
2450 * Map the block we are given ready for reading. There are three possible return
2451 * values:
2452 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
2453 * caller knows not to execute a subsequent read.
2454 * 0 - if we mapped the block successfully
2455 * >0 - positive error number if there was an error.
2456 */
2457static int
2458xfs_dabuf_map(
2459 struct xfs_inode *dp,
2460 xfs_dablk_t bno,
2461 xfs_daddr_t mappedbno,
2462 int whichfork,
2463 struct xfs_buf_map **map,
2464 int *nmaps)
2465{
2466 struct xfs_mount *mp = dp->i_mount;
2467 int nfsb;
2468 int error = 0;
2469 struct xfs_bmbt_irec irec;
2470 struct xfs_bmbt_irec *irecs = &irec;
2471 int nirecs;
2472
2473 ASSERT(map && *map);
2474 ASSERT(*nmaps == 1);
2475
2476 if (whichfork == XFS_DATA_FORK)
2477 nfsb = mp->m_dir_geo->fsbcount;
2478 else
2479 nfsb = mp->m_attr_geo->fsbcount;
2480
2481 /*
2482 * Caller doesn't have a mapping. -2 means don't complain
2483 * if we land in a hole.
2484 */
2485 if (mappedbno == -1 || mappedbno == -2) {
2486 /*
2487 * Optimize the one-block case.
2488 */
2489 if (nfsb != 1)
2490 irecs = kmem_zalloc(sizeof(irec) * nfsb,
2491 KM_SLEEP | KM_NOFS);
2492
2493 nirecs = nfsb;
2494 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2495 &nirecs, xfs_bmapi_aflag(whichfork));
2496 if (error)
2497 goto out;
2498 } else {
2499 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2500 irecs->br_startoff = (xfs_fileoff_t)bno;
2501 irecs->br_blockcount = nfsb;
2502 irecs->br_state = 0;
2503 nirecs = 1;
2504 }
2505
2506 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2507 error = mappedbno == -2 ? -1 : -EFSCORRUPTED;
2508 if (unlikely(error == -EFSCORRUPTED)) {
2509 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2510 int i;
2511 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2512 __func__, (long long)bno,
2513 (long long)dp->i_ino);
2514 for (i = 0; i < *nmaps; i++) {
2515 xfs_alert(mp,
2516"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2517 i,
2518 (long long)irecs[i].br_startoff,
2519 (long long)irecs[i].br_startblock,
2520 (long long)irecs[i].br_blockcount,
2521 irecs[i].br_state);
2522 }
2523 }
2524 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2525 XFS_ERRLEVEL_LOW, mp);
2526 }
2527 goto out;
2528 }
2529 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2530out:
2531 if (irecs != &irec)
2532 kmem_free(irecs);
2533 return error;
2534}
2535
2536/*
2537 * Get a buffer for the dir/attr block.
2538 */
2539int
2540xfs_da_get_buf(
2541 struct xfs_trans *trans,
2542 struct xfs_inode *dp,
2543 xfs_dablk_t bno,
2544 xfs_daddr_t mappedbno,
2545 struct xfs_buf **bpp,
2546 int whichfork)
2547{
2548 struct xfs_buf *bp;
2549 struct xfs_buf_map map;
2550 struct xfs_buf_map *mapp;
2551 int nmap;
2552 int error;
2553
2554 *bpp = NULL;
2555 mapp = ↦
2556 nmap = 1;
2557 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2558 &mapp, &nmap);
2559 if (error) {
2560 /* mapping a hole is not an error, but we don't continue */
2561 if (error == -1)
2562 error = 0;
2563 goto out_free;
2564 }
2565
2566 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2567 mapp, nmap, 0);
2568 error = bp ? bp->b_error : -EIO;
2569 if (error) {
2570 if (bp)
2571 xfs_trans_brelse(trans, bp);
2572 goto out_free;
2573 }
2574
2575 *bpp = bp;
2576
2577out_free:
2578 if (mapp != &map)
2579 kmem_free(mapp);
2580
2581 return error;
2582}
2583
2584/*
2585 * Get a buffer for the dir/attr block, fill in the contents.
2586 */
2587int
2588xfs_da_read_buf(
2589 struct xfs_trans *trans,
2590 struct xfs_inode *dp,
2591 xfs_dablk_t bno,
2592 xfs_daddr_t mappedbno,
2593 struct xfs_buf **bpp,
2594 int whichfork,
2595 const struct xfs_buf_ops *ops)
2596{
2597 struct xfs_buf *bp;
2598 struct xfs_buf_map map;
2599 struct xfs_buf_map *mapp;
2600 int nmap;
2601 int error;
2602
2603 *bpp = NULL;
2604 mapp = ↦
2605 nmap = 1;
2606 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2607 &mapp, &nmap);
2608 if (error) {
2609 /* mapping a hole is not an error, but we don't continue */
2610 if (error == -1)
2611 error = 0;
2612 goto out_free;
2613 }
2614
2615 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2616 dp->i_mount->m_ddev_targp,
2617 mapp, nmap, 0, &bp, ops);
2618 if (error)
2619 goto out_free;
2620
2621 if (whichfork == XFS_ATTR_FORK)
2622 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2623 else
2624 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2625 *bpp = bp;
2626out_free:
2627 if (mapp != &map)
2628 kmem_free(mapp);
2629
2630 return error;
2631}
2632
2633/*
2634 * Readahead the dir/attr block.
2635 */
2636int
2637xfs_da_reada_buf(
2638 struct xfs_inode *dp,
2639 xfs_dablk_t bno,
2640 xfs_daddr_t mappedbno,
2641 int whichfork,
2642 const struct xfs_buf_ops *ops)
2643{
2644 struct xfs_buf_map map;
2645 struct xfs_buf_map *mapp;
2646 int nmap;
2647 int error;
2648
2649 mapp = ↦
2650 nmap = 1;
2651 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2652 &mapp, &nmap);
2653 if (error) {
2654 /* mapping a hole is not an error, but we don't continue */
2655 if (error == -1)
2656 error = 0;
2657 goto out_free;
2658 }
2659
2660 mappedbno = mapp[0].bm_bn;
2661 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2662
2663out_free:
2664 if (mapp != &map)
2665 kmem_free(mapp);
2666
2667 return error;
2668}
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 /* fall through */
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_d.di_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_d.di_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}