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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_sb.h"
27#include "xfs_ag.h"
28#include "xfs_mount.h"
29#include "xfs_da_format.h"
30#include "xfs_da_btree.h"
31#include "xfs_dir2.h"
32#include "xfs_dir2_priv.h"
33#include "xfs_inode.h"
34#include "xfs_trans.h"
35#include "xfs_inode_item.h"
36#include "xfs_alloc.h"
37#include "xfs_bmap.h"
38#include "xfs_attr.h"
39#include "xfs_attr_leaf.h"
40#include "xfs_error.h"
41#include "xfs_trace.h"
42#include "xfs_cksum.h"
43#include "xfs_buf_item.h"
44
45/*
46 * xfs_da_btree.c
47 *
48 * Routines to implement directories as Btrees of hashed names.
49 */
50
51/*========================================================================
52 * Function prototypes for the kernel.
53 *========================================================================*/
54
55/*
56 * Routines used for growing the Btree.
57 */
58STATIC int xfs_da3_root_split(xfs_da_state_t *state,
59 xfs_da_state_blk_t *existing_root,
60 xfs_da_state_blk_t *new_child);
61STATIC int xfs_da3_node_split(xfs_da_state_t *state,
62 xfs_da_state_blk_t *existing_blk,
63 xfs_da_state_blk_t *split_blk,
64 xfs_da_state_blk_t *blk_to_add,
65 int treelevel,
66 int *result);
67STATIC void xfs_da3_node_rebalance(xfs_da_state_t *state,
68 xfs_da_state_blk_t *node_blk_1,
69 xfs_da_state_blk_t *node_blk_2);
70STATIC void xfs_da3_node_add(xfs_da_state_t *state,
71 xfs_da_state_blk_t *old_node_blk,
72 xfs_da_state_blk_t *new_node_blk);
73
74/*
75 * Routines used for shrinking the Btree.
76 */
77STATIC int xfs_da3_root_join(xfs_da_state_t *state,
78 xfs_da_state_blk_t *root_blk);
79STATIC int xfs_da3_node_toosmall(xfs_da_state_t *state, int *retval);
80STATIC void xfs_da3_node_remove(xfs_da_state_t *state,
81 xfs_da_state_blk_t *drop_blk);
82STATIC void xfs_da3_node_unbalance(xfs_da_state_t *state,
83 xfs_da_state_blk_t *src_node_blk,
84 xfs_da_state_blk_t *dst_node_blk);
85
86/*
87 * Utility routines.
88 */
89STATIC int xfs_da3_blk_unlink(xfs_da_state_t *state,
90 xfs_da_state_blk_t *drop_blk,
91 xfs_da_state_blk_t *save_blk);
92
93
94kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
95
96/*
97 * Allocate a dir-state structure.
98 * We don't put them on the stack since they're large.
99 */
100xfs_da_state_t *
101xfs_da_state_alloc(void)
102{
103 return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
104}
105
106/*
107 * Kill the altpath contents of a da-state structure.
108 */
109STATIC void
110xfs_da_state_kill_altpath(xfs_da_state_t *state)
111{
112 int i;
113
114 for (i = 0; i < state->altpath.active; i++)
115 state->altpath.blk[i].bp = NULL;
116 state->altpath.active = 0;
117}
118
119/*
120 * Free a da-state structure.
121 */
122void
123xfs_da_state_free(xfs_da_state_t *state)
124{
125 xfs_da_state_kill_altpath(state);
126#ifdef DEBUG
127 memset((char *)state, 0, sizeof(*state));
128#endif /* DEBUG */
129 kmem_zone_free(xfs_da_state_zone, state);
130}
131
132static bool
133xfs_da3_node_verify(
134 struct xfs_buf *bp)
135{
136 struct xfs_mount *mp = bp->b_target->bt_mount;
137 struct xfs_da_intnode *hdr = bp->b_addr;
138 struct xfs_da3_icnode_hdr ichdr;
139 const struct xfs_dir_ops *ops;
140
141 ops = xfs_dir_get_ops(mp, NULL);
142
143 ops->node_hdr_from_disk(&ichdr, hdr);
144
145 if (xfs_sb_version_hascrc(&mp->m_sb)) {
146 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
147
148 if (ichdr.magic != XFS_DA3_NODE_MAGIC)
149 return false;
150
151 if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_uuid))
152 return false;
153 if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn)
154 return false;
155 } else {
156 if (ichdr.magic != XFS_DA_NODE_MAGIC)
157 return false;
158 }
159 if (ichdr.level == 0)
160 return false;
161 if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
162 return false;
163 if (ichdr.count == 0)
164 return false;
165
166 /*
167 * we don't know if the node is for and attribute or directory tree,
168 * so only fail if the count is outside both bounds
169 */
170 if (ichdr.count > mp->m_dir_geo->node_ents &&
171 ichdr.count > mp->m_attr_geo->node_ents)
172 return false;
173
174 /* XXX: hash order check? */
175
176 return true;
177}
178
179static void
180xfs_da3_node_write_verify(
181 struct xfs_buf *bp)
182{
183 struct xfs_mount *mp = bp->b_target->bt_mount;
184 struct xfs_buf_log_item *bip = bp->b_fspriv;
185 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
186
187 if (!xfs_da3_node_verify(bp)) {
188 xfs_buf_ioerror(bp, -EFSCORRUPTED);
189 xfs_verifier_error(bp);
190 return;
191 }
192
193 if (!xfs_sb_version_hascrc(&mp->m_sb))
194 return;
195
196 if (bip)
197 hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
198
199 xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
200}
201
202/*
203 * leaf/node format detection on trees is sketchy, so a node read can be done on
204 * leaf level blocks when detection identifies the tree as a node format tree
205 * incorrectly. In this case, we need to swap the verifier to match the correct
206 * format of the block being read.
207 */
208static void
209xfs_da3_node_read_verify(
210 struct xfs_buf *bp)
211{
212 struct xfs_da_blkinfo *info = bp->b_addr;
213
214 switch (be16_to_cpu(info->magic)) {
215 case XFS_DA3_NODE_MAGIC:
216 if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
217 xfs_buf_ioerror(bp, -EFSBADCRC);
218 break;
219 }
220 /* fall through */
221 case XFS_DA_NODE_MAGIC:
222 if (!xfs_da3_node_verify(bp)) {
223 xfs_buf_ioerror(bp, -EFSCORRUPTED);
224 break;
225 }
226 return;
227 case XFS_ATTR_LEAF_MAGIC:
228 case XFS_ATTR3_LEAF_MAGIC:
229 bp->b_ops = &xfs_attr3_leaf_buf_ops;
230 bp->b_ops->verify_read(bp);
231 return;
232 case XFS_DIR2_LEAFN_MAGIC:
233 case XFS_DIR3_LEAFN_MAGIC:
234 bp->b_ops = &xfs_dir3_leafn_buf_ops;
235 bp->b_ops->verify_read(bp);
236 return;
237 default:
238 break;
239 }
240
241 /* corrupt block */
242 xfs_verifier_error(bp);
243}
244
245const struct xfs_buf_ops xfs_da3_node_buf_ops = {
246 .verify_read = xfs_da3_node_read_verify,
247 .verify_write = xfs_da3_node_write_verify,
248};
249
250int
251xfs_da3_node_read(
252 struct xfs_trans *tp,
253 struct xfs_inode *dp,
254 xfs_dablk_t bno,
255 xfs_daddr_t mappedbno,
256 struct xfs_buf **bpp,
257 int which_fork)
258{
259 int err;
260
261 err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
262 which_fork, &xfs_da3_node_buf_ops);
263 if (!err && tp) {
264 struct xfs_da_blkinfo *info = (*bpp)->b_addr;
265 int type;
266
267 switch (be16_to_cpu(info->magic)) {
268 case XFS_DA_NODE_MAGIC:
269 case XFS_DA3_NODE_MAGIC:
270 type = XFS_BLFT_DA_NODE_BUF;
271 break;
272 case XFS_ATTR_LEAF_MAGIC:
273 case XFS_ATTR3_LEAF_MAGIC:
274 type = XFS_BLFT_ATTR_LEAF_BUF;
275 break;
276 case XFS_DIR2_LEAFN_MAGIC:
277 case XFS_DIR3_LEAFN_MAGIC:
278 type = XFS_BLFT_DIR_LEAFN_BUF;
279 break;
280 default:
281 type = 0;
282 ASSERT(0);
283 break;
284 }
285 xfs_trans_buf_set_type(tp, *bpp, type);
286 }
287 return err;
288}
289
290/*========================================================================
291 * Routines used for growing the Btree.
292 *========================================================================*/
293
294/*
295 * Create the initial contents of an intermediate node.
296 */
297int
298xfs_da3_node_create(
299 struct xfs_da_args *args,
300 xfs_dablk_t blkno,
301 int level,
302 struct xfs_buf **bpp,
303 int whichfork)
304{
305 struct xfs_da_intnode *node;
306 struct xfs_trans *tp = args->trans;
307 struct xfs_mount *mp = tp->t_mountp;
308 struct xfs_da3_icnode_hdr ichdr = {0};
309 struct xfs_buf *bp;
310 int error;
311 struct xfs_inode *dp = args->dp;
312
313 trace_xfs_da_node_create(args);
314 ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
315
316 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, whichfork);
317 if (error)
318 return error;
319 bp->b_ops = &xfs_da3_node_buf_ops;
320 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
321 node = bp->b_addr;
322
323 if (xfs_sb_version_hascrc(&mp->m_sb)) {
324 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
325
326 ichdr.magic = XFS_DA3_NODE_MAGIC;
327 hdr3->info.blkno = cpu_to_be64(bp->b_bn);
328 hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
329 uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_uuid);
330 } else {
331 ichdr.magic = XFS_DA_NODE_MAGIC;
332 }
333 ichdr.level = level;
334
335 dp->d_ops->node_hdr_to_disk(node, &ichdr);
336 xfs_trans_log_buf(tp, bp,
337 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
338
339 *bpp = bp;
340 return 0;
341}
342
343/*
344 * Split a leaf node, rebalance, then possibly split
345 * intermediate nodes, rebalance, etc.
346 */
347int /* error */
348xfs_da3_split(
349 struct xfs_da_state *state)
350{
351 struct xfs_da_state_blk *oldblk;
352 struct xfs_da_state_blk *newblk;
353 struct xfs_da_state_blk *addblk;
354 struct xfs_da_intnode *node;
355 struct xfs_buf *bp;
356 int max;
357 int action = 0;
358 int error;
359 int i;
360
361 trace_xfs_da_split(state->args);
362
363 /*
364 * Walk back up the tree splitting/inserting/adjusting as necessary.
365 * If we need to insert and there isn't room, split the node, then
366 * decide which fragment to insert the new block from below into.
367 * Note that we may split the root this way, but we need more fixup.
368 */
369 max = state->path.active - 1;
370 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
371 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
372 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
373
374 addblk = &state->path.blk[max]; /* initial dummy value */
375 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
376 oldblk = &state->path.blk[i];
377 newblk = &state->altpath.blk[i];
378
379 /*
380 * If a leaf node then
381 * Allocate a new leaf node, then rebalance across them.
382 * else if an intermediate node then
383 * We split on the last layer, must we split the node?
384 */
385 switch (oldblk->magic) {
386 case XFS_ATTR_LEAF_MAGIC:
387 error = xfs_attr3_leaf_split(state, oldblk, newblk);
388 if ((error != 0) && (error != -ENOSPC)) {
389 return error; /* GROT: attr is inconsistent */
390 }
391 if (!error) {
392 addblk = newblk;
393 break;
394 }
395 /*
396 * Entry wouldn't fit, split the leaf again.
397 */
398 state->extravalid = 1;
399 if (state->inleaf) {
400 state->extraafter = 0; /* before newblk */
401 trace_xfs_attr_leaf_split_before(state->args);
402 error = xfs_attr3_leaf_split(state, oldblk,
403 &state->extrablk);
404 } else {
405 state->extraafter = 1; /* after newblk */
406 trace_xfs_attr_leaf_split_after(state->args);
407 error = xfs_attr3_leaf_split(state, newblk,
408 &state->extrablk);
409 }
410 if (error)
411 return error; /* GROT: attr inconsistent */
412 addblk = newblk;
413 break;
414 case XFS_DIR2_LEAFN_MAGIC:
415 error = xfs_dir2_leafn_split(state, oldblk, newblk);
416 if (error)
417 return error;
418 addblk = newblk;
419 break;
420 case XFS_DA_NODE_MAGIC:
421 error = xfs_da3_node_split(state, oldblk, newblk, addblk,
422 max - i, &action);
423 addblk->bp = NULL;
424 if (error)
425 return error; /* GROT: dir is inconsistent */
426 /*
427 * Record the newly split block for the next time thru?
428 */
429 if (action)
430 addblk = newblk;
431 else
432 addblk = NULL;
433 break;
434 }
435
436 /*
437 * Update the btree to show the new hashval for this child.
438 */
439 xfs_da3_fixhashpath(state, &state->path);
440 }
441 if (!addblk)
442 return 0;
443
444 /*
445 * Split the root node.
446 */
447 ASSERT(state->path.active == 0);
448 oldblk = &state->path.blk[0];
449 error = xfs_da3_root_split(state, oldblk, addblk);
450 if (error) {
451 addblk->bp = NULL;
452 return error; /* GROT: dir is inconsistent */
453 }
454
455 /*
456 * Update pointers to the node which used to be block 0 and
457 * just got bumped because of the addition of a new root node.
458 * There might be three blocks involved if a double split occurred,
459 * and the original block 0 could be at any position in the list.
460 *
461 * Note: the magic numbers and sibling pointers are in the same
462 * physical place for both v2 and v3 headers (by design). Hence it
463 * doesn't matter which version of the xfs_da_intnode structure we use
464 * here as the result will be the same using either structure.
465 */
466 node = oldblk->bp->b_addr;
467 if (node->hdr.info.forw) {
468 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
469 bp = addblk->bp;
470 } else {
471 ASSERT(state->extravalid);
472 bp = state->extrablk.bp;
473 }
474 node = bp->b_addr;
475 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
476 xfs_trans_log_buf(state->args->trans, bp,
477 XFS_DA_LOGRANGE(node, &node->hdr.info,
478 sizeof(node->hdr.info)));
479 }
480 node = oldblk->bp->b_addr;
481 if (node->hdr.info.back) {
482 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
483 bp = addblk->bp;
484 } else {
485 ASSERT(state->extravalid);
486 bp = state->extrablk.bp;
487 }
488 node = bp->b_addr;
489 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
490 xfs_trans_log_buf(state->args->trans, bp,
491 XFS_DA_LOGRANGE(node, &node->hdr.info,
492 sizeof(node->hdr.info)));
493 }
494 addblk->bp = NULL;
495 return 0;
496}
497
498/*
499 * Split the root. We have to create a new root and point to the two
500 * parts (the split old root) that we just created. Copy block zero to
501 * the EOF, extending the inode in process.
502 */
503STATIC int /* error */
504xfs_da3_root_split(
505 struct xfs_da_state *state,
506 struct xfs_da_state_blk *blk1,
507 struct xfs_da_state_blk *blk2)
508{
509 struct xfs_da_intnode *node;
510 struct xfs_da_intnode *oldroot;
511 struct xfs_da_node_entry *btree;
512 struct xfs_da3_icnode_hdr nodehdr;
513 struct xfs_da_args *args;
514 struct xfs_buf *bp;
515 struct xfs_inode *dp;
516 struct xfs_trans *tp;
517 struct xfs_mount *mp;
518 struct xfs_dir2_leaf *leaf;
519 xfs_dablk_t blkno;
520 int level;
521 int error;
522 int size;
523
524 trace_xfs_da_root_split(state->args);
525
526 /*
527 * Copy the existing (incorrect) block from the root node position
528 * to a free space somewhere.
529 */
530 args = state->args;
531 error = xfs_da_grow_inode(args, &blkno);
532 if (error)
533 return error;
534
535 dp = args->dp;
536 tp = args->trans;
537 mp = state->mp;
538 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
539 if (error)
540 return error;
541 node = bp->b_addr;
542 oldroot = blk1->bp->b_addr;
543 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
544 oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
545 struct xfs_da3_icnode_hdr nodehdr;
546
547 dp->d_ops->node_hdr_from_disk(&nodehdr, oldroot);
548 btree = dp->d_ops->node_tree_p(oldroot);
549 size = (int)((char *)&btree[nodehdr.count] - (char *)oldroot);
550 level = nodehdr.level;
551
552 /*
553 * we are about to copy oldroot to bp, so set up the type
554 * of bp while we know exactly what it will be.
555 */
556 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
557 } else {
558 struct xfs_dir3_icleaf_hdr leafhdr;
559 struct xfs_dir2_leaf_entry *ents;
560
561 leaf = (xfs_dir2_leaf_t *)oldroot;
562 dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
563 ents = dp->d_ops->leaf_ents_p(leaf);
564
565 ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
566 leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
567 size = (int)((char *)&ents[leafhdr.count] - (char *)leaf);
568 level = 0;
569
570 /*
571 * we are about to copy oldroot to bp, so set up the type
572 * of bp while we know exactly what it will be.
573 */
574 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
575 }
576
577 /*
578 * we can copy most of the information in the node from one block to
579 * another, but for CRC enabled headers we have to make sure that the
580 * block specific identifiers are kept intact. We update the buffer
581 * directly for this.
582 */
583 memcpy(node, oldroot, size);
584 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
585 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
586 struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
587
588 node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
589 }
590 xfs_trans_log_buf(tp, bp, 0, size - 1);
591
592 bp->b_ops = blk1->bp->b_ops;
593 xfs_trans_buf_copy_type(bp, blk1->bp);
594 blk1->bp = bp;
595 blk1->blkno = blkno;
596
597 /*
598 * Set up the new root node.
599 */
600 error = xfs_da3_node_create(args,
601 (args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
602 level + 1, &bp, args->whichfork);
603 if (error)
604 return error;
605
606 node = bp->b_addr;
607 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
608 btree = dp->d_ops->node_tree_p(node);
609 btree[0].hashval = cpu_to_be32(blk1->hashval);
610 btree[0].before = cpu_to_be32(blk1->blkno);
611 btree[1].hashval = cpu_to_be32(blk2->hashval);
612 btree[1].before = cpu_to_be32(blk2->blkno);
613 nodehdr.count = 2;
614 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
615
616#ifdef DEBUG
617 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
618 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
619 ASSERT(blk1->blkno >= args->geo->leafblk &&
620 blk1->blkno < args->geo->freeblk);
621 ASSERT(blk2->blkno >= args->geo->leafblk &&
622 blk2->blkno < args->geo->freeblk);
623 }
624#endif
625
626 /* Header is already logged by xfs_da_node_create */
627 xfs_trans_log_buf(tp, bp,
628 XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
629
630 return 0;
631}
632
633/*
634 * Split the node, rebalance, then add the new entry.
635 */
636STATIC int /* error */
637xfs_da3_node_split(
638 struct xfs_da_state *state,
639 struct xfs_da_state_blk *oldblk,
640 struct xfs_da_state_blk *newblk,
641 struct xfs_da_state_blk *addblk,
642 int treelevel,
643 int *result)
644{
645 struct xfs_da_intnode *node;
646 struct xfs_da3_icnode_hdr nodehdr;
647 xfs_dablk_t blkno;
648 int newcount;
649 int error;
650 int useextra;
651 struct xfs_inode *dp = state->args->dp;
652
653 trace_xfs_da_node_split(state->args);
654
655 node = oldblk->bp->b_addr;
656 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
657
658 /*
659 * With V2 dirs the extra block is data or freespace.
660 */
661 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
662 newcount = 1 + useextra;
663 /*
664 * Do we have to split the node?
665 */
666 if (nodehdr.count + newcount > state->args->geo->node_ents) {
667 /*
668 * Allocate a new node, add to the doubly linked chain of
669 * nodes, then move some of our excess entries into it.
670 */
671 error = xfs_da_grow_inode(state->args, &blkno);
672 if (error)
673 return error; /* GROT: dir is inconsistent */
674
675 error = xfs_da3_node_create(state->args, blkno, treelevel,
676 &newblk->bp, state->args->whichfork);
677 if (error)
678 return error; /* GROT: dir is inconsistent */
679 newblk->blkno = blkno;
680 newblk->magic = XFS_DA_NODE_MAGIC;
681 xfs_da3_node_rebalance(state, oldblk, newblk);
682 error = xfs_da3_blk_link(state, oldblk, newblk);
683 if (error)
684 return error;
685 *result = 1;
686 } else {
687 *result = 0;
688 }
689
690 /*
691 * Insert the new entry(s) into the correct block
692 * (updating last hashval in the process).
693 *
694 * xfs_da3_node_add() inserts BEFORE the given index,
695 * and as a result of using node_lookup_int() we always
696 * point to a valid entry (not after one), but a split
697 * operation always results in a new block whose hashvals
698 * FOLLOW the current block.
699 *
700 * If we had double-split op below us, then add the extra block too.
701 */
702 node = oldblk->bp->b_addr;
703 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
704 if (oldblk->index <= nodehdr.count) {
705 oldblk->index++;
706 xfs_da3_node_add(state, oldblk, addblk);
707 if (useextra) {
708 if (state->extraafter)
709 oldblk->index++;
710 xfs_da3_node_add(state, oldblk, &state->extrablk);
711 state->extravalid = 0;
712 }
713 } else {
714 newblk->index++;
715 xfs_da3_node_add(state, newblk, addblk);
716 if (useextra) {
717 if (state->extraafter)
718 newblk->index++;
719 xfs_da3_node_add(state, newblk, &state->extrablk);
720 state->extravalid = 0;
721 }
722 }
723
724 return 0;
725}
726
727/*
728 * Balance the btree elements between two intermediate nodes,
729 * usually one full and one empty.
730 *
731 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
732 */
733STATIC void
734xfs_da3_node_rebalance(
735 struct xfs_da_state *state,
736 struct xfs_da_state_blk *blk1,
737 struct xfs_da_state_blk *blk2)
738{
739 struct xfs_da_intnode *node1;
740 struct xfs_da_intnode *node2;
741 struct xfs_da_intnode *tmpnode;
742 struct xfs_da_node_entry *btree1;
743 struct xfs_da_node_entry *btree2;
744 struct xfs_da_node_entry *btree_s;
745 struct xfs_da_node_entry *btree_d;
746 struct xfs_da3_icnode_hdr nodehdr1;
747 struct xfs_da3_icnode_hdr nodehdr2;
748 struct xfs_trans *tp;
749 int count;
750 int tmp;
751 int swap = 0;
752 struct xfs_inode *dp = state->args->dp;
753
754 trace_xfs_da_node_rebalance(state->args);
755
756 node1 = blk1->bp->b_addr;
757 node2 = blk2->bp->b_addr;
758 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
759 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
760 btree1 = dp->d_ops->node_tree_p(node1);
761 btree2 = dp->d_ops->node_tree_p(node2);
762
763 /*
764 * Figure out how many entries need to move, and in which direction.
765 * Swap the nodes around if that makes it simpler.
766 */
767 if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
768 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
769 (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
770 be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
771 tmpnode = node1;
772 node1 = node2;
773 node2 = tmpnode;
774 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
775 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
776 btree1 = dp->d_ops->node_tree_p(node1);
777 btree2 = dp->d_ops->node_tree_p(node2);
778 swap = 1;
779 }
780
781 count = (nodehdr1.count - nodehdr2.count) / 2;
782 if (count == 0)
783 return;
784 tp = state->args->trans;
785 /*
786 * Two cases: high-to-low and low-to-high.
787 */
788 if (count > 0) {
789 /*
790 * Move elements in node2 up to make a hole.
791 */
792 tmp = nodehdr2.count;
793 if (tmp > 0) {
794 tmp *= (uint)sizeof(xfs_da_node_entry_t);
795 btree_s = &btree2[0];
796 btree_d = &btree2[count];
797 memmove(btree_d, btree_s, tmp);
798 }
799
800 /*
801 * Move the req'd B-tree elements from high in node1 to
802 * low in node2.
803 */
804 nodehdr2.count += count;
805 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
806 btree_s = &btree1[nodehdr1.count - count];
807 btree_d = &btree2[0];
808 memcpy(btree_d, btree_s, tmp);
809 nodehdr1.count -= count;
810 } else {
811 /*
812 * Move the req'd B-tree elements from low in node2 to
813 * high in node1.
814 */
815 count = -count;
816 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
817 btree_s = &btree2[0];
818 btree_d = &btree1[nodehdr1.count];
819 memcpy(btree_d, btree_s, tmp);
820 nodehdr1.count += count;
821
822 xfs_trans_log_buf(tp, blk1->bp,
823 XFS_DA_LOGRANGE(node1, btree_d, tmp));
824
825 /*
826 * Move elements in node2 down to fill the hole.
827 */
828 tmp = nodehdr2.count - count;
829 tmp *= (uint)sizeof(xfs_da_node_entry_t);
830 btree_s = &btree2[count];
831 btree_d = &btree2[0];
832 memmove(btree_d, btree_s, tmp);
833 nodehdr2.count -= count;
834 }
835
836 /*
837 * Log header of node 1 and all current bits of node 2.
838 */
839 dp->d_ops->node_hdr_to_disk(node1, &nodehdr1);
840 xfs_trans_log_buf(tp, blk1->bp,
841 XFS_DA_LOGRANGE(node1, &node1->hdr, dp->d_ops->node_hdr_size));
842
843 dp->d_ops->node_hdr_to_disk(node2, &nodehdr2);
844 xfs_trans_log_buf(tp, blk2->bp,
845 XFS_DA_LOGRANGE(node2, &node2->hdr,
846 dp->d_ops->node_hdr_size +
847 (sizeof(btree2[0]) * nodehdr2.count)));
848
849 /*
850 * Record the last hashval from each block for upward propagation.
851 * (note: don't use the swapped node pointers)
852 */
853 if (swap) {
854 node1 = blk1->bp->b_addr;
855 node2 = blk2->bp->b_addr;
856 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
857 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
858 btree1 = dp->d_ops->node_tree_p(node1);
859 btree2 = dp->d_ops->node_tree_p(node2);
860 }
861 blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
862 blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
863
864 /*
865 * Adjust the expected index for insertion.
866 */
867 if (blk1->index >= nodehdr1.count) {
868 blk2->index = blk1->index - nodehdr1.count;
869 blk1->index = nodehdr1.count + 1; /* make it invalid */
870 }
871}
872
873/*
874 * Add a new entry to an intermediate node.
875 */
876STATIC void
877xfs_da3_node_add(
878 struct xfs_da_state *state,
879 struct xfs_da_state_blk *oldblk,
880 struct xfs_da_state_blk *newblk)
881{
882 struct xfs_da_intnode *node;
883 struct xfs_da3_icnode_hdr nodehdr;
884 struct xfs_da_node_entry *btree;
885 int tmp;
886 struct xfs_inode *dp = state->args->dp;
887
888 trace_xfs_da_node_add(state->args);
889
890 node = oldblk->bp->b_addr;
891 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
892 btree = dp->d_ops->node_tree_p(node);
893
894 ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
895 ASSERT(newblk->blkno != 0);
896 if (state->args->whichfork == XFS_DATA_FORK)
897 ASSERT(newblk->blkno >= state->args->geo->leafblk &&
898 newblk->blkno < state->args->geo->freeblk);
899
900 /*
901 * We may need to make some room before we insert the new node.
902 */
903 tmp = 0;
904 if (oldblk->index < nodehdr.count) {
905 tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
906 memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
907 }
908 btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
909 btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
910 xfs_trans_log_buf(state->args->trans, oldblk->bp,
911 XFS_DA_LOGRANGE(node, &btree[oldblk->index],
912 tmp + sizeof(*btree)));
913
914 nodehdr.count += 1;
915 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
916 xfs_trans_log_buf(state->args->trans, oldblk->bp,
917 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
918
919 /*
920 * Copy the last hash value from the oldblk to propagate upwards.
921 */
922 oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
923}
924
925/*========================================================================
926 * Routines used for shrinking the Btree.
927 *========================================================================*/
928
929/*
930 * Deallocate an empty leaf node, remove it from its parent,
931 * possibly deallocating that block, etc...
932 */
933int
934xfs_da3_join(
935 struct xfs_da_state *state)
936{
937 struct xfs_da_state_blk *drop_blk;
938 struct xfs_da_state_blk *save_blk;
939 int action = 0;
940 int error;
941
942 trace_xfs_da_join(state->args);
943
944 drop_blk = &state->path.blk[ state->path.active-1 ];
945 save_blk = &state->altpath.blk[ state->path.active-1 ];
946 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
947 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
948 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
949
950 /*
951 * Walk back up the tree joining/deallocating as necessary.
952 * When we stop dropping blocks, break out.
953 */
954 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
955 state->path.active--) {
956 /*
957 * See if we can combine the block with a neighbor.
958 * (action == 0) => no options, just leave
959 * (action == 1) => coalesce, then unlink
960 * (action == 2) => block empty, unlink it
961 */
962 switch (drop_blk->magic) {
963 case XFS_ATTR_LEAF_MAGIC:
964 error = xfs_attr3_leaf_toosmall(state, &action);
965 if (error)
966 return error;
967 if (action == 0)
968 return 0;
969 xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
970 break;
971 case XFS_DIR2_LEAFN_MAGIC:
972 error = xfs_dir2_leafn_toosmall(state, &action);
973 if (error)
974 return error;
975 if (action == 0)
976 return 0;
977 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
978 break;
979 case XFS_DA_NODE_MAGIC:
980 /*
981 * Remove the offending node, fixup hashvals,
982 * check for a toosmall neighbor.
983 */
984 xfs_da3_node_remove(state, drop_blk);
985 xfs_da3_fixhashpath(state, &state->path);
986 error = xfs_da3_node_toosmall(state, &action);
987 if (error)
988 return error;
989 if (action == 0)
990 return 0;
991 xfs_da3_node_unbalance(state, drop_blk, save_blk);
992 break;
993 }
994 xfs_da3_fixhashpath(state, &state->altpath);
995 error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
996 xfs_da_state_kill_altpath(state);
997 if (error)
998 return error;
999 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1000 drop_blk->bp);
1001 drop_blk->bp = NULL;
1002 if (error)
1003 return error;
1004 }
1005 /*
1006 * We joined all the way to the top. If it turns out that
1007 * we only have one entry in the root, make the child block
1008 * the new root.
1009 */
1010 xfs_da3_node_remove(state, drop_blk);
1011 xfs_da3_fixhashpath(state, &state->path);
1012 error = xfs_da3_root_join(state, &state->path.blk[0]);
1013 return error;
1014}
1015
1016#ifdef DEBUG
1017static void
1018xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1019{
1020 __be16 magic = blkinfo->magic;
1021
1022 if (level == 1) {
1023 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1024 magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1025 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1026 magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1027 } else {
1028 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1029 magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1030 }
1031 ASSERT(!blkinfo->forw);
1032 ASSERT(!blkinfo->back);
1033}
1034#else /* !DEBUG */
1035#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1036#endif /* !DEBUG */
1037
1038/*
1039 * We have only one entry in the root. Copy the only remaining child of
1040 * the old root to block 0 as the new root node.
1041 */
1042STATIC int
1043xfs_da3_root_join(
1044 struct xfs_da_state *state,
1045 struct xfs_da_state_blk *root_blk)
1046{
1047 struct xfs_da_intnode *oldroot;
1048 struct xfs_da_args *args;
1049 xfs_dablk_t child;
1050 struct xfs_buf *bp;
1051 struct xfs_da3_icnode_hdr oldroothdr;
1052 struct xfs_da_node_entry *btree;
1053 int error;
1054 struct xfs_inode *dp = state->args->dp;
1055
1056 trace_xfs_da_root_join(state->args);
1057
1058 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1059
1060 args = state->args;
1061 oldroot = root_blk->bp->b_addr;
1062 dp->d_ops->node_hdr_from_disk(&oldroothdr, oldroot);
1063 ASSERT(oldroothdr.forw == 0);
1064 ASSERT(oldroothdr.back == 0);
1065
1066 /*
1067 * If the root has more than one child, then don't do anything.
1068 */
1069 if (oldroothdr.count > 1)
1070 return 0;
1071
1072 /*
1073 * Read in the (only) child block, then copy those bytes into
1074 * the root block's buffer and free the original child block.
1075 */
1076 btree = dp->d_ops->node_tree_p(oldroot);
1077 child = be32_to_cpu(btree[0].before);
1078 ASSERT(child != 0);
1079 error = xfs_da3_node_read(args->trans, dp, child, -1, &bp,
1080 args->whichfork);
1081 if (error)
1082 return error;
1083 xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1084
1085 /*
1086 * This could be copying a leaf back into the root block in the case of
1087 * there only being a single leaf block left in the tree. Hence we have
1088 * to update the b_ops pointer as well to match the buffer type change
1089 * that could occur. For dir3 blocks we also need to update the block
1090 * number in the buffer header.
1091 */
1092 memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1093 root_blk->bp->b_ops = bp->b_ops;
1094 xfs_trans_buf_copy_type(root_blk->bp, bp);
1095 if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1096 struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1097 da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
1098 }
1099 xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1100 args->geo->blksize - 1);
1101 error = xfs_da_shrink_inode(args, child, bp);
1102 return error;
1103}
1104
1105/*
1106 * Check a node block and its neighbors to see if the block should be
1107 * collapsed into one or the other neighbor. Always keep the block
1108 * with the smaller block number.
1109 * If the current block is over 50% full, don't try to join it, return 0.
1110 * If the block is empty, fill in the state structure and return 2.
1111 * If it can be collapsed, fill in the state structure and return 1.
1112 * If nothing can be done, return 0.
1113 */
1114STATIC int
1115xfs_da3_node_toosmall(
1116 struct xfs_da_state *state,
1117 int *action)
1118{
1119 struct xfs_da_intnode *node;
1120 struct xfs_da_state_blk *blk;
1121 struct xfs_da_blkinfo *info;
1122 xfs_dablk_t blkno;
1123 struct xfs_buf *bp;
1124 struct xfs_da3_icnode_hdr nodehdr;
1125 int count;
1126 int forward;
1127 int error;
1128 int retval;
1129 int i;
1130 struct xfs_inode *dp = state->args->dp;
1131
1132 trace_xfs_da_node_toosmall(state->args);
1133
1134 /*
1135 * Check for the degenerate case of the block being over 50% full.
1136 * If so, it's not worth even looking to see if we might be able
1137 * to coalesce with a sibling.
1138 */
1139 blk = &state->path.blk[ state->path.active-1 ];
1140 info = blk->bp->b_addr;
1141 node = (xfs_da_intnode_t *)info;
1142 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1143 if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1144 *action = 0; /* blk over 50%, don't try to join */
1145 return 0; /* blk over 50%, don't try to join */
1146 }
1147
1148 /*
1149 * Check for the degenerate case of the block being empty.
1150 * If the block is empty, we'll simply delete it, no need to
1151 * coalesce it with a sibling block. We choose (arbitrarily)
1152 * to merge with the forward block unless it is NULL.
1153 */
1154 if (nodehdr.count == 0) {
1155 /*
1156 * Make altpath point to the block we want to keep and
1157 * path point to the block we want to drop (this one).
1158 */
1159 forward = (info->forw != 0);
1160 memcpy(&state->altpath, &state->path, sizeof(state->path));
1161 error = xfs_da3_path_shift(state, &state->altpath, forward,
1162 0, &retval);
1163 if (error)
1164 return error;
1165 if (retval) {
1166 *action = 0;
1167 } else {
1168 *action = 2;
1169 }
1170 return 0;
1171 }
1172
1173 /*
1174 * Examine each sibling block to see if we can coalesce with
1175 * at least 25% free space to spare. We need to figure out
1176 * whether to merge with the forward or the backward block.
1177 * We prefer coalescing with the lower numbered sibling so as
1178 * to shrink a directory over time.
1179 */
1180 count = state->args->geo->node_ents;
1181 count -= state->args->geo->node_ents >> 2;
1182 count -= nodehdr.count;
1183
1184 /* start with smaller blk num */
1185 forward = nodehdr.forw < nodehdr.back;
1186 for (i = 0; i < 2; forward = !forward, i++) {
1187 struct xfs_da3_icnode_hdr thdr;
1188 if (forward)
1189 blkno = nodehdr.forw;
1190 else
1191 blkno = nodehdr.back;
1192 if (blkno == 0)
1193 continue;
1194 error = xfs_da3_node_read(state->args->trans, dp,
1195 blkno, -1, &bp, state->args->whichfork);
1196 if (error)
1197 return error;
1198
1199 node = bp->b_addr;
1200 dp->d_ops->node_hdr_from_disk(&thdr, node);
1201 xfs_trans_brelse(state->args->trans, bp);
1202
1203 if (count - thdr.count >= 0)
1204 break; /* fits with at least 25% to spare */
1205 }
1206 if (i >= 2) {
1207 *action = 0;
1208 return 0;
1209 }
1210
1211 /*
1212 * Make altpath point to the block we want to keep (the lower
1213 * numbered block) and path point to the block we want to drop.
1214 */
1215 memcpy(&state->altpath, &state->path, sizeof(state->path));
1216 if (blkno < blk->blkno) {
1217 error = xfs_da3_path_shift(state, &state->altpath, forward,
1218 0, &retval);
1219 } else {
1220 error = xfs_da3_path_shift(state, &state->path, forward,
1221 0, &retval);
1222 }
1223 if (error)
1224 return error;
1225 if (retval) {
1226 *action = 0;
1227 return 0;
1228 }
1229 *action = 1;
1230 return 0;
1231}
1232
1233/*
1234 * Pick up the last hashvalue from an intermediate node.
1235 */
1236STATIC uint
1237xfs_da3_node_lasthash(
1238 struct xfs_inode *dp,
1239 struct xfs_buf *bp,
1240 int *count)
1241{
1242 struct xfs_da_intnode *node;
1243 struct xfs_da_node_entry *btree;
1244 struct xfs_da3_icnode_hdr nodehdr;
1245
1246 node = bp->b_addr;
1247 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1248 if (count)
1249 *count = nodehdr.count;
1250 if (!nodehdr.count)
1251 return 0;
1252 btree = dp->d_ops->node_tree_p(node);
1253 return be32_to_cpu(btree[nodehdr.count - 1].hashval);
1254}
1255
1256/*
1257 * Walk back up the tree adjusting hash values as necessary,
1258 * when we stop making changes, return.
1259 */
1260void
1261xfs_da3_fixhashpath(
1262 struct xfs_da_state *state,
1263 struct xfs_da_state_path *path)
1264{
1265 struct xfs_da_state_blk *blk;
1266 struct xfs_da_intnode *node;
1267 struct xfs_da_node_entry *btree;
1268 xfs_dahash_t lasthash=0;
1269 int level;
1270 int count;
1271 struct xfs_inode *dp = state->args->dp;
1272
1273 trace_xfs_da_fixhashpath(state->args);
1274
1275 level = path->active-1;
1276 blk = &path->blk[ level ];
1277 switch (blk->magic) {
1278 case XFS_ATTR_LEAF_MAGIC:
1279 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1280 if (count == 0)
1281 return;
1282 break;
1283 case XFS_DIR2_LEAFN_MAGIC:
1284 lasthash = xfs_dir2_leafn_lasthash(dp, blk->bp, &count);
1285 if (count == 0)
1286 return;
1287 break;
1288 case XFS_DA_NODE_MAGIC:
1289 lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1290 if (count == 0)
1291 return;
1292 break;
1293 }
1294 for (blk--, level--; level >= 0; blk--, level--) {
1295 struct xfs_da3_icnode_hdr nodehdr;
1296
1297 node = blk->bp->b_addr;
1298 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1299 btree = dp->d_ops->node_tree_p(node);
1300 if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1301 break;
1302 blk->hashval = lasthash;
1303 btree[blk->index].hashval = cpu_to_be32(lasthash);
1304 xfs_trans_log_buf(state->args->trans, blk->bp,
1305 XFS_DA_LOGRANGE(node, &btree[blk->index],
1306 sizeof(*btree)));
1307
1308 lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1309 }
1310}
1311
1312/*
1313 * Remove an entry from an intermediate node.
1314 */
1315STATIC void
1316xfs_da3_node_remove(
1317 struct xfs_da_state *state,
1318 struct xfs_da_state_blk *drop_blk)
1319{
1320 struct xfs_da_intnode *node;
1321 struct xfs_da3_icnode_hdr nodehdr;
1322 struct xfs_da_node_entry *btree;
1323 int index;
1324 int tmp;
1325 struct xfs_inode *dp = state->args->dp;
1326
1327 trace_xfs_da_node_remove(state->args);
1328
1329 node = drop_blk->bp->b_addr;
1330 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1331 ASSERT(drop_blk->index < nodehdr.count);
1332 ASSERT(drop_blk->index >= 0);
1333
1334 /*
1335 * Copy over the offending entry, or just zero it out.
1336 */
1337 index = drop_blk->index;
1338 btree = dp->d_ops->node_tree_p(node);
1339 if (index < nodehdr.count - 1) {
1340 tmp = nodehdr.count - index - 1;
1341 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1342 memmove(&btree[index], &btree[index + 1], tmp);
1343 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1344 XFS_DA_LOGRANGE(node, &btree[index], tmp));
1345 index = nodehdr.count - 1;
1346 }
1347 memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1348 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1349 XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1350 nodehdr.count -= 1;
1351 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
1352 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1353 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
1354
1355 /*
1356 * Copy the last hash value from the block to propagate upwards.
1357 */
1358 drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1359}
1360
1361/*
1362 * Unbalance the elements between two intermediate nodes,
1363 * move all Btree elements from one node into another.
1364 */
1365STATIC void
1366xfs_da3_node_unbalance(
1367 struct xfs_da_state *state,
1368 struct xfs_da_state_blk *drop_blk,
1369 struct xfs_da_state_blk *save_blk)
1370{
1371 struct xfs_da_intnode *drop_node;
1372 struct xfs_da_intnode *save_node;
1373 struct xfs_da_node_entry *drop_btree;
1374 struct xfs_da_node_entry *save_btree;
1375 struct xfs_da3_icnode_hdr drop_hdr;
1376 struct xfs_da3_icnode_hdr save_hdr;
1377 struct xfs_trans *tp;
1378 int sindex;
1379 int tmp;
1380 struct xfs_inode *dp = state->args->dp;
1381
1382 trace_xfs_da_node_unbalance(state->args);
1383
1384 drop_node = drop_blk->bp->b_addr;
1385 save_node = save_blk->bp->b_addr;
1386 dp->d_ops->node_hdr_from_disk(&drop_hdr, drop_node);
1387 dp->d_ops->node_hdr_from_disk(&save_hdr, save_node);
1388 drop_btree = dp->d_ops->node_tree_p(drop_node);
1389 save_btree = dp->d_ops->node_tree_p(save_node);
1390 tp = state->args->trans;
1391
1392 /*
1393 * If the dying block has lower hashvals, then move all the
1394 * elements in the remaining block up to make a hole.
1395 */
1396 if ((be32_to_cpu(drop_btree[0].hashval) <
1397 be32_to_cpu(save_btree[0].hashval)) ||
1398 (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1399 be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1400 /* XXX: check this - is memmove dst correct? */
1401 tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1402 memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1403
1404 sindex = 0;
1405 xfs_trans_log_buf(tp, save_blk->bp,
1406 XFS_DA_LOGRANGE(save_node, &save_btree[0],
1407 (save_hdr.count + drop_hdr.count) *
1408 sizeof(xfs_da_node_entry_t)));
1409 } else {
1410 sindex = save_hdr.count;
1411 xfs_trans_log_buf(tp, save_blk->bp,
1412 XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1413 drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1414 }
1415
1416 /*
1417 * Move all the B-tree elements from drop_blk to save_blk.
1418 */
1419 tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1420 memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1421 save_hdr.count += drop_hdr.count;
1422
1423 dp->d_ops->node_hdr_to_disk(save_node, &save_hdr);
1424 xfs_trans_log_buf(tp, save_blk->bp,
1425 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1426 dp->d_ops->node_hdr_size));
1427
1428 /*
1429 * Save the last hashval in the remaining block for upward propagation.
1430 */
1431 save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1432}
1433
1434/*========================================================================
1435 * Routines used for finding things in the Btree.
1436 *========================================================================*/
1437
1438/*
1439 * Walk down the Btree looking for a particular filename, filling
1440 * in the state structure as we go.
1441 *
1442 * We will set the state structure to point to each of the elements
1443 * in each of the nodes where either the hashval is or should be.
1444 *
1445 * We support duplicate hashval's so for each entry in the current
1446 * node that could contain the desired hashval, descend. This is a
1447 * pruned depth-first tree search.
1448 */
1449int /* error */
1450xfs_da3_node_lookup_int(
1451 struct xfs_da_state *state,
1452 int *result)
1453{
1454 struct xfs_da_state_blk *blk;
1455 struct xfs_da_blkinfo *curr;
1456 struct xfs_da_intnode *node;
1457 struct xfs_da_node_entry *btree;
1458 struct xfs_da3_icnode_hdr nodehdr;
1459 struct xfs_da_args *args;
1460 xfs_dablk_t blkno;
1461 xfs_dahash_t hashval;
1462 xfs_dahash_t btreehashval;
1463 int probe;
1464 int span;
1465 int max;
1466 int error;
1467 int retval;
1468 struct xfs_inode *dp = state->args->dp;
1469
1470 args = state->args;
1471
1472 /*
1473 * Descend thru the B-tree searching each level for the right
1474 * node to use, until the right hashval is found.
1475 */
1476 blkno = (args->whichfork == XFS_DATA_FORK)? args->geo->leafblk : 0;
1477 for (blk = &state->path.blk[0], state->path.active = 1;
1478 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1479 blk++, state->path.active++) {
1480 /*
1481 * Read the next node down in the tree.
1482 */
1483 blk->blkno = blkno;
1484 error = xfs_da3_node_read(args->trans, args->dp, blkno,
1485 -1, &blk->bp, args->whichfork);
1486 if (error) {
1487 blk->blkno = 0;
1488 state->path.active--;
1489 return error;
1490 }
1491 curr = blk->bp->b_addr;
1492 blk->magic = be16_to_cpu(curr->magic);
1493
1494 if (blk->magic == XFS_ATTR_LEAF_MAGIC ||
1495 blk->magic == XFS_ATTR3_LEAF_MAGIC) {
1496 blk->magic = XFS_ATTR_LEAF_MAGIC;
1497 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1498 break;
1499 }
1500
1501 if (blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1502 blk->magic == XFS_DIR3_LEAFN_MAGIC) {
1503 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1504 blk->hashval = xfs_dir2_leafn_lasthash(args->dp,
1505 blk->bp, NULL);
1506 break;
1507 }
1508
1509 blk->magic = XFS_DA_NODE_MAGIC;
1510
1511
1512 /*
1513 * Search an intermediate node for a match.
1514 */
1515 node = blk->bp->b_addr;
1516 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1517 btree = dp->d_ops->node_tree_p(node);
1518
1519 max = nodehdr.count;
1520 blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1521
1522 /*
1523 * Binary search. (note: small blocks will skip loop)
1524 */
1525 probe = span = max / 2;
1526 hashval = args->hashval;
1527 while (span > 4) {
1528 span /= 2;
1529 btreehashval = be32_to_cpu(btree[probe].hashval);
1530 if (btreehashval < hashval)
1531 probe += span;
1532 else if (btreehashval > hashval)
1533 probe -= span;
1534 else
1535 break;
1536 }
1537 ASSERT((probe >= 0) && (probe < max));
1538 ASSERT((span <= 4) ||
1539 (be32_to_cpu(btree[probe].hashval) == hashval));
1540
1541 /*
1542 * Since we may have duplicate hashval's, find the first
1543 * matching hashval in the node.
1544 */
1545 while (probe > 0 &&
1546 be32_to_cpu(btree[probe].hashval) >= hashval) {
1547 probe--;
1548 }
1549 while (probe < max &&
1550 be32_to_cpu(btree[probe].hashval) < hashval) {
1551 probe++;
1552 }
1553
1554 /*
1555 * Pick the right block to descend on.
1556 */
1557 if (probe == max) {
1558 blk->index = max - 1;
1559 blkno = be32_to_cpu(btree[max - 1].before);
1560 } else {
1561 blk->index = probe;
1562 blkno = be32_to_cpu(btree[probe].before);
1563 }
1564 }
1565
1566 /*
1567 * A leaf block that ends in the hashval that we are interested in
1568 * (final hashval == search hashval) means that the next block may
1569 * contain more entries with the same hashval, shift upward to the
1570 * next leaf and keep searching.
1571 */
1572 for (;;) {
1573 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1574 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1575 &blk->index, state);
1576 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1577 retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1578 blk->index = args->index;
1579 args->blkno = blk->blkno;
1580 } else {
1581 ASSERT(0);
1582 return -EFSCORRUPTED;
1583 }
1584 if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1585 (blk->hashval == args->hashval)) {
1586 error = xfs_da3_path_shift(state, &state->path, 1, 1,
1587 &retval);
1588 if (error)
1589 return error;
1590 if (retval == 0) {
1591 continue;
1592 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1593 /* path_shift() gives ENOENT */
1594 retval = -ENOATTR;
1595 }
1596 }
1597 break;
1598 }
1599 *result = retval;
1600 return 0;
1601}
1602
1603/*========================================================================
1604 * Utility routines.
1605 *========================================================================*/
1606
1607/*
1608 * Compare two intermediate nodes for "order".
1609 */
1610STATIC int
1611xfs_da3_node_order(
1612 struct xfs_inode *dp,
1613 struct xfs_buf *node1_bp,
1614 struct xfs_buf *node2_bp)
1615{
1616 struct xfs_da_intnode *node1;
1617 struct xfs_da_intnode *node2;
1618 struct xfs_da_node_entry *btree1;
1619 struct xfs_da_node_entry *btree2;
1620 struct xfs_da3_icnode_hdr node1hdr;
1621 struct xfs_da3_icnode_hdr node2hdr;
1622
1623 node1 = node1_bp->b_addr;
1624 node2 = node2_bp->b_addr;
1625 dp->d_ops->node_hdr_from_disk(&node1hdr, node1);
1626 dp->d_ops->node_hdr_from_disk(&node2hdr, node2);
1627 btree1 = dp->d_ops->node_tree_p(node1);
1628 btree2 = dp->d_ops->node_tree_p(node2);
1629
1630 if (node1hdr.count > 0 && node2hdr.count > 0 &&
1631 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1632 (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1633 be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1634 return 1;
1635 }
1636 return 0;
1637}
1638
1639/*
1640 * Link a new block into a doubly linked list of blocks (of whatever type).
1641 */
1642int /* error */
1643xfs_da3_blk_link(
1644 struct xfs_da_state *state,
1645 struct xfs_da_state_blk *old_blk,
1646 struct xfs_da_state_blk *new_blk)
1647{
1648 struct xfs_da_blkinfo *old_info;
1649 struct xfs_da_blkinfo *new_info;
1650 struct xfs_da_blkinfo *tmp_info;
1651 struct xfs_da_args *args;
1652 struct xfs_buf *bp;
1653 int before = 0;
1654 int error;
1655 struct xfs_inode *dp = state->args->dp;
1656
1657 /*
1658 * Set up environment.
1659 */
1660 args = state->args;
1661 ASSERT(args != NULL);
1662 old_info = old_blk->bp->b_addr;
1663 new_info = new_blk->bp->b_addr;
1664 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1665 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1666 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1667
1668 switch (old_blk->magic) {
1669 case XFS_ATTR_LEAF_MAGIC:
1670 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1671 break;
1672 case XFS_DIR2_LEAFN_MAGIC:
1673 before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1674 break;
1675 case XFS_DA_NODE_MAGIC:
1676 before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1677 break;
1678 }
1679
1680 /*
1681 * Link blocks in appropriate order.
1682 */
1683 if (before) {
1684 /*
1685 * Link new block in before existing block.
1686 */
1687 trace_xfs_da_link_before(args);
1688 new_info->forw = cpu_to_be32(old_blk->blkno);
1689 new_info->back = old_info->back;
1690 if (old_info->back) {
1691 error = xfs_da3_node_read(args->trans, dp,
1692 be32_to_cpu(old_info->back),
1693 -1, &bp, args->whichfork);
1694 if (error)
1695 return error;
1696 ASSERT(bp != NULL);
1697 tmp_info = bp->b_addr;
1698 ASSERT(tmp_info->magic == old_info->magic);
1699 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1700 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1701 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1702 }
1703 old_info->back = cpu_to_be32(new_blk->blkno);
1704 } else {
1705 /*
1706 * Link new block in after existing block.
1707 */
1708 trace_xfs_da_link_after(args);
1709 new_info->forw = old_info->forw;
1710 new_info->back = cpu_to_be32(old_blk->blkno);
1711 if (old_info->forw) {
1712 error = xfs_da3_node_read(args->trans, dp,
1713 be32_to_cpu(old_info->forw),
1714 -1, &bp, args->whichfork);
1715 if (error)
1716 return error;
1717 ASSERT(bp != NULL);
1718 tmp_info = bp->b_addr;
1719 ASSERT(tmp_info->magic == old_info->magic);
1720 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1721 tmp_info->back = cpu_to_be32(new_blk->blkno);
1722 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1723 }
1724 old_info->forw = cpu_to_be32(new_blk->blkno);
1725 }
1726
1727 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1728 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1729 return 0;
1730}
1731
1732/*
1733 * Unlink a block from a doubly linked list of blocks.
1734 */
1735STATIC int /* error */
1736xfs_da3_blk_unlink(
1737 struct xfs_da_state *state,
1738 struct xfs_da_state_blk *drop_blk,
1739 struct xfs_da_state_blk *save_blk)
1740{
1741 struct xfs_da_blkinfo *drop_info;
1742 struct xfs_da_blkinfo *save_info;
1743 struct xfs_da_blkinfo *tmp_info;
1744 struct xfs_da_args *args;
1745 struct xfs_buf *bp;
1746 int error;
1747
1748 /*
1749 * Set up environment.
1750 */
1751 args = state->args;
1752 ASSERT(args != NULL);
1753 save_info = save_blk->bp->b_addr;
1754 drop_info = drop_blk->bp->b_addr;
1755 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1756 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1757 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1758 ASSERT(save_blk->magic == drop_blk->magic);
1759 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1760 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1761 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1762 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1763
1764 /*
1765 * Unlink the leaf block from the doubly linked chain of leaves.
1766 */
1767 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1768 trace_xfs_da_unlink_back(args);
1769 save_info->back = drop_info->back;
1770 if (drop_info->back) {
1771 error = xfs_da3_node_read(args->trans, args->dp,
1772 be32_to_cpu(drop_info->back),
1773 -1, &bp, args->whichfork);
1774 if (error)
1775 return error;
1776 ASSERT(bp != NULL);
1777 tmp_info = bp->b_addr;
1778 ASSERT(tmp_info->magic == save_info->magic);
1779 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1780 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1781 xfs_trans_log_buf(args->trans, bp, 0,
1782 sizeof(*tmp_info) - 1);
1783 }
1784 } else {
1785 trace_xfs_da_unlink_forward(args);
1786 save_info->forw = drop_info->forw;
1787 if (drop_info->forw) {
1788 error = xfs_da3_node_read(args->trans, args->dp,
1789 be32_to_cpu(drop_info->forw),
1790 -1, &bp, args->whichfork);
1791 if (error)
1792 return error;
1793 ASSERT(bp != NULL);
1794 tmp_info = bp->b_addr;
1795 ASSERT(tmp_info->magic == save_info->magic);
1796 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1797 tmp_info->back = cpu_to_be32(save_blk->blkno);
1798 xfs_trans_log_buf(args->trans, bp, 0,
1799 sizeof(*tmp_info) - 1);
1800 }
1801 }
1802
1803 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1804 return 0;
1805}
1806
1807/*
1808 * Move a path "forward" or "!forward" one block at the current level.
1809 *
1810 * This routine will adjust a "path" to point to the next block
1811 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1812 * Btree, including updating pointers to the intermediate nodes between
1813 * the new bottom and the root.
1814 */
1815int /* error */
1816xfs_da3_path_shift(
1817 struct xfs_da_state *state,
1818 struct xfs_da_state_path *path,
1819 int forward,
1820 int release,
1821 int *result)
1822{
1823 struct xfs_da_state_blk *blk;
1824 struct xfs_da_blkinfo *info;
1825 struct xfs_da_intnode *node;
1826 struct xfs_da_args *args;
1827 struct xfs_da_node_entry *btree;
1828 struct xfs_da3_icnode_hdr nodehdr;
1829 xfs_dablk_t blkno = 0;
1830 int level;
1831 int error;
1832 struct xfs_inode *dp = state->args->dp;
1833
1834 trace_xfs_da_path_shift(state->args);
1835
1836 /*
1837 * Roll up the Btree looking for the first block where our
1838 * current index is not at the edge of the block. Note that
1839 * we skip the bottom layer because we want the sibling block.
1840 */
1841 args = state->args;
1842 ASSERT(args != NULL);
1843 ASSERT(path != NULL);
1844 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1845 level = (path->active-1) - 1; /* skip bottom layer in path */
1846 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1847 node = blk->bp->b_addr;
1848 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1849 btree = dp->d_ops->node_tree_p(node);
1850
1851 if (forward && (blk->index < nodehdr.count - 1)) {
1852 blk->index++;
1853 blkno = be32_to_cpu(btree[blk->index].before);
1854 break;
1855 } else if (!forward && (blk->index > 0)) {
1856 blk->index--;
1857 blkno = be32_to_cpu(btree[blk->index].before);
1858 break;
1859 }
1860 }
1861 if (level < 0) {
1862 *result = -ENOENT; /* we're out of our tree */
1863 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1864 return 0;
1865 }
1866
1867 /*
1868 * Roll down the edge of the subtree until we reach the
1869 * same depth we were at originally.
1870 */
1871 for (blk++, level++; level < path->active; blk++, level++) {
1872 /*
1873 * Release the old block.
1874 * (if it's dirty, trans won't actually let go)
1875 */
1876 if (release)
1877 xfs_trans_brelse(args->trans, blk->bp);
1878
1879 /*
1880 * Read the next child block.
1881 */
1882 blk->blkno = blkno;
1883 error = xfs_da3_node_read(args->trans, dp, blkno, -1,
1884 &blk->bp, args->whichfork);
1885 if (error)
1886 return error;
1887 info = blk->bp->b_addr;
1888 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1889 info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
1890 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1891 info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1892 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1893 info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1894
1895
1896 /*
1897 * Note: we flatten the magic number to a single type so we
1898 * don't have to compare against crc/non-crc types elsewhere.
1899 */
1900 switch (be16_to_cpu(info->magic)) {
1901 case XFS_DA_NODE_MAGIC:
1902 case XFS_DA3_NODE_MAGIC:
1903 blk->magic = XFS_DA_NODE_MAGIC;
1904 node = (xfs_da_intnode_t *)info;
1905 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1906 btree = dp->d_ops->node_tree_p(node);
1907 blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1908 if (forward)
1909 blk->index = 0;
1910 else
1911 blk->index = nodehdr.count - 1;
1912 blkno = be32_to_cpu(btree[blk->index].before);
1913 break;
1914 case XFS_ATTR_LEAF_MAGIC:
1915 case XFS_ATTR3_LEAF_MAGIC:
1916 blk->magic = XFS_ATTR_LEAF_MAGIC;
1917 ASSERT(level == path->active-1);
1918 blk->index = 0;
1919 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1920 break;
1921 case XFS_DIR2_LEAFN_MAGIC:
1922 case XFS_DIR3_LEAFN_MAGIC:
1923 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1924 ASSERT(level == path->active-1);
1925 blk->index = 0;
1926 blk->hashval = xfs_dir2_leafn_lasthash(args->dp,
1927 blk->bp, NULL);
1928 break;
1929 default:
1930 ASSERT(0);
1931 break;
1932 }
1933 }
1934 *result = 0;
1935 return 0;
1936}
1937
1938
1939/*========================================================================
1940 * Utility routines.
1941 *========================================================================*/
1942
1943/*
1944 * Implement a simple hash on a character string.
1945 * Rotate the hash value by 7 bits, then XOR each character in.
1946 * This is implemented with some source-level loop unrolling.
1947 */
1948xfs_dahash_t
1949xfs_da_hashname(const __uint8_t *name, int namelen)
1950{
1951 xfs_dahash_t hash;
1952
1953 /*
1954 * Do four characters at a time as long as we can.
1955 */
1956 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1957 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1958 (name[3] << 0) ^ rol32(hash, 7 * 4);
1959
1960 /*
1961 * Now do the rest of the characters.
1962 */
1963 switch (namelen) {
1964 case 3:
1965 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1966 rol32(hash, 7 * 3);
1967 case 2:
1968 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1969 case 1:
1970 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1971 default: /* case 0: */
1972 return hash;
1973 }
1974}
1975
1976enum xfs_dacmp
1977xfs_da_compname(
1978 struct xfs_da_args *args,
1979 const unsigned char *name,
1980 int len)
1981{
1982 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1983 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1984}
1985
1986static xfs_dahash_t
1987xfs_default_hashname(
1988 struct xfs_name *name)
1989{
1990 return xfs_da_hashname(name->name, name->len);
1991}
1992
1993const struct xfs_nameops xfs_default_nameops = {
1994 .hashname = xfs_default_hashname,
1995 .compname = xfs_da_compname
1996};
1997
1998int
1999xfs_da_grow_inode_int(
2000 struct xfs_da_args *args,
2001 xfs_fileoff_t *bno,
2002 int count)
2003{
2004 struct xfs_trans *tp = args->trans;
2005 struct xfs_inode *dp = args->dp;
2006 int w = args->whichfork;
2007 xfs_drfsbno_t nblks = dp->i_d.di_nblocks;
2008 struct xfs_bmbt_irec map, *mapp;
2009 int nmap, error, got, i, mapi;
2010
2011 /*
2012 * Find a spot in the file space to put the new block.
2013 */
2014 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2015 if (error)
2016 return error;
2017
2018 /*
2019 * Try mapping it in one filesystem block.
2020 */
2021 nmap = 1;
2022 ASSERT(args->firstblock != NULL);
2023 error = xfs_bmapi_write(tp, dp, *bno, count,
2024 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2025 args->firstblock, args->total, &map, &nmap,
2026 args->flist);
2027 if (error)
2028 return error;
2029
2030 ASSERT(nmap <= 1);
2031 if (nmap == 1) {
2032 mapp = &map;
2033 mapi = 1;
2034 } else if (nmap == 0 && count > 1) {
2035 xfs_fileoff_t b;
2036 int c;
2037
2038 /*
2039 * If we didn't get it and the block might work if fragmented,
2040 * try without the CONTIG flag. Loop until we get it all.
2041 */
2042 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
2043 for (b = *bno, mapi = 0; b < *bno + count; ) {
2044 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
2045 c = (int)(*bno + count - b);
2046 error = xfs_bmapi_write(tp, dp, b, c,
2047 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2048 args->firstblock, args->total,
2049 &mapp[mapi], &nmap, args->flist);
2050 if (error)
2051 goto out_free_map;
2052 if (nmap < 1)
2053 break;
2054 mapi += nmap;
2055 b = mapp[mapi - 1].br_startoff +
2056 mapp[mapi - 1].br_blockcount;
2057 }
2058 } else {
2059 mapi = 0;
2060 mapp = NULL;
2061 }
2062
2063 /*
2064 * Count the blocks we got, make sure it matches the total.
2065 */
2066 for (i = 0, got = 0; i < mapi; i++)
2067 got += mapp[i].br_blockcount;
2068 if (got != count || mapp[0].br_startoff != *bno ||
2069 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2070 *bno + count) {
2071 error = -ENOSPC;
2072 goto out_free_map;
2073 }
2074
2075 /* account for newly allocated blocks in reserved blocks total */
2076 args->total -= dp->i_d.di_nblocks - nblks;
2077
2078out_free_map:
2079 if (mapp != &map)
2080 kmem_free(mapp);
2081 return error;
2082}
2083
2084/*
2085 * Add a block to the btree ahead of the file.
2086 * Return the new block number to the caller.
2087 */
2088int
2089xfs_da_grow_inode(
2090 struct xfs_da_args *args,
2091 xfs_dablk_t *new_blkno)
2092{
2093 xfs_fileoff_t bno;
2094 int error;
2095
2096 trace_xfs_da_grow_inode(args);
2097
2098 bno = args->geo->leafblk;
2099 error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2100 if (!error)
2101 *new_blkno = (xfs_dablk_t)bno;
2102 return error;
2103}
2104
2105/*
2106 * Ick. We need to always be able to remove a btree block, even
2107 * if there's no space reservation because the filesystem is full.
2108 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2109 * It swaps the target block with the last block in the file. The
2110 * last block in the file can always be removed since it can't cause
2111 * a bmap btree split to do that.
2112 */
2113STATIC int
2114xfs_da3_swap_lastblock(
2115 struct xfs_da_args *args,
2116 xfs_dablk_t *dead_blknop,
2117 struct xfs_buf **dead_bufp)
2118{
2119 struct xfs_da_blkinfo *dead_info;
2120 struct xfs_da_blkinfo *sib_info;
2121 struct xfs_da_intnode *par_node;
2122 struct xfs_da_intnode *dead_node;
2123 struct xfs_dir2_leaf *dead_leaf2;
2124 struct xfs_da_node_entry *btree;
2125 struct xfs_da3_icnode_hdr par_hdr;
2126 struct xfs_inode *dp;
2127 struct xfs_trans *tp;
2128 struct xfs_mount *mp;
2129 struct xfs_buf *dead_buf;
2130 struct xfs_buf *last_buf;
2131 struct xfs_buf *sib_buf;
2132 struct xfs_buf *par_buf;
2133 xfs_dahash_t dead_hash;
2134 xfs_fileoff_t lastoff;
2135 xfs_dablk_t dead_blkno;
2136 xfs_dablk_t last_blkno;
2137 xfs_dablk_t sib_blkno;
2138 xfs_dablk_t par_blkno;
2139 int error;
2140 int w;
2141 int entno;
2142 int level;
2143 int dead_level;
2144
2145 trace_xfs_da_swap_lastblock(args);
2146
2147 dead_buf = *dead_bufp;
2148 dead_blkno = *dead_blknop;
2149 tp = args->trans;
2150 dp = args->dp;
2151 w = args->whichfork;
2152 ASSERT(w == XFS_DATA_FORK);
2153 mp = dp->i_mount;
2154 lastoff = args->geo->freeblk;
2155 error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2156 if (error)
2157 return error;
2158 if (unlikely(lastoff == 0)) {
2159 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
2160 mp);
2161 return -EFSCORRUPTED;
2162 }
2163 /*
2164 * Read the last block in the btree space.
2165 */
2166 last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2167 error = xfs_da3_node_read(tp, dp, last_blkno, -1, &last_buf, w);
2168 if (error)
2169 return error;
2170 /*
2171 * Copy the last block into the dead buffer and log it.
2172 */
2173 memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2174 xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2175 dead_info = dead_buf->b_addr;
2176 /*
2177 * Get values from the moved block.
2178 */
2179 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2180 dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2181 struct xfs_dir3_icleaf_hdr leafhdr;
2182 struct xfs_dir2_leaf_entry *ents;
2183
2184 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2185 dp->d_ops->leaf_hdr_from_disk(&leafhdr, dead_leaf2);
2186 ents = dp->d_ops->leaf_ents_p(dead_leaf2);
2187 dead_level = 0;
2188 dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2189 } else {
2190 struct xfs_da3_icnode_hdr deadhdr;
2191
2192 dead_node = (xfs_da_intnode_t *)dead_info;
2193 dp->d_ops->node_hdr_from_disk(&deadhdr, dead_node);
2194 btree = dp->d_ops->node_tree_p(dead_node);
2195 dead_level = deadhdr.level;
2196 dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2197 }
2198 sib_buf = par_buf = NULL;
2199 /*
2200 * If the moved block has a left sibling, fix up the pointers.
2201 */
2202 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2203 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2204 if (error)
2205 goto done;
2206 sib_info = sib_buf->b_addr;
2207 if (unlikely(
2208 be32_to_cpu(sib_info->forw) != last_blkno ||
2209 sib_info->magic != dead_info->magic)) {
2210 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
2211 XFS_ERRLEVEL_LOW, mp);
2212 error = -EFSCORRUPTED;
2213 goto done;
2214 }
2215 sib_info->forw = cpu_to_be32(dead_blkno);
2216 xfs_trans_log_buf(tp, sib_buf,
2217 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2218 sizeof(sib_info->forw)));
2219 sib_buf = NULL;
2220 }
2221 /*
2222 * If the moved block has a right sibling, fix up the pointers.
2223 */
2224 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2225 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2226 if (error)
2227 goto done;
2228 sib_info = sib_buf->b_addr;
2229 if (unlikely(
2230 be32_to_cpu(sib_info->back) != last_blkno ||
2231 sib_info->magic != dead_info->magic)) {
2232 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
2233 XFS_ERRLEVEL_LOW, mp);
2234 error = -EFSCORRUPTED;
2235 goto done;
2236 }
2237 sib_info->back = cpu_to_be32(dead_blkno);
2238 xfs_trans_log_buf(tp, sib_buf,
2239 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2240 sizeof(sib_info->back)));
2241 sib_buf = NULL;
2242 }
2243 par_blkno = args->geo->leafblk;
2244 level = -1;
2245 /*
2246 * Walk down the tree looking for the parent of the moved block.
2247 */
2248 for (;;) {
2249 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2250 if (error)
2251 goto done;
2252 par_node = par_buf->b_addr;
2253 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2254 if (level >= 0 && level != par_hdr.level + 1) {
2255 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
2256 XFS_ERRLEVEL_LOW, mp);
2257 error = -EFSCORRUPTED;
2258 goto done;
2259 }
2260 level = par_hdr.level;
2261 btree = dp->d_ops->node_tree_p(par_node);
2262 for (entno = 0;
2263 entno < par_hdr.count &&
2264 be32_to_cpu(btree[entno].hashval) < dead_hash;
2265 entno++)
2266 continue;
2267 if (entno == par_hdr.count) {
2268 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
2269 XFS_ERRLEVEL_LOW, mp);
2270 error = -EFSCORRUPTED;
2271 goto done;
2272 }
2273 par_blkno = be32_to_cpu(btree[entno].before);
2274 if (level == dead_level + 1)
2275 break;
2276 xfs_trans_brelse(tp, par_buf);
2277 par_buf = NULL;
2278 }
2279 /*
2280 * We're in the right parent block.
2281 * Look for the right entry.
2282 */
2283 for (;;) {
2284 for (;
2285 entno < par_hdr.count &&
2286 be32_to_cpu(btree[entno].before) != last_blkno;
2287 entno++)
2288 continue;
2289 if (entno < par_hdr.count)
2290 break;
2291 par_blkno = par_hdr.forw;
2292 xfs_trans_brelse(tp, par_buf);
2293 par_buf = NULL;
2294 if (unlikely(par_blkno == 0)) {
2295 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
2296 XFS_ERRLEVEL_LOW, mp);
2297 error = -EFSCORRUPTED;
2298 goto done;
2299 }
2300 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2301 if (error)
2302 goto done;
2303 par_node = par_buf->b_addr;
2304 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2305 if (par_hdr.level != level) {
2306 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
2307 XFS_ERRLEVEL_LOW, mp);
2308 error = -EFSCORRUPTED;
2309 goto done;
2310 }
2311 btree = dp->d_ops->node_tree_p(par_node);
2312 entno = 0;
2313 }
2314 /*
2315 * Update the parent entry pointing to the moved block.
2316 */
2317 btree[entno].before = cpu_to_be32(dead_blkno);
2318 xfs_trans_log_buf(tp, par_buf,
2319 XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2320 sizeof(btree[entno].before)));
2321 *dead_blknop = last_blkno;
2322 *dead_bufp = last_buf;
2323 return 0;
2324done:
2325 if (par_buf)
2326 xfs_trans_brelse(tp, par_buf);
2327 if (sib_buf)
2328 xfs_trans_brelse(tp, sib_buf);
2329 xfs_trans_brelse(tp, last_buf);
2330 return error;
2331}
2332
2333/*
2334 * Remove a btree block from a directory or attribute.
2335 */
2336int
2337xfs_da_shrink_inode(
2338 xfs_da_args_t *args,
2339 xfs_dablk_t dead_blkno,
2340 struct xfs_buf *dead_buf)
2341{
2342 xfs_inode_t *dp;
2343 int done, error, w, count;
2344 xfs_trans_t *tp;
2345 xfs_mount_t *mp;
2346
2347 trace_xfs_da_shrink_inode(args);
2348
2349 dp = args->dp;
2350 w = args->whichfork;
2351 tp = args->trans;
2352 mp = dp->i_mount;
2353 count = args->geo->fsbcount;
2354 for (;;) {
2355 /*
2356 * Remove extents. If we get ENOSPC for a dir we have to move
2357 * the last block to the place we want to kill.
2358 */
2359 error = xfs_bunmapi(tp, dp, dead_blkno, count,
2360 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2361 0, args->firstblock, args->flist, &done);
2362 if (error == -ENOSPC) {
2363 if (w != XFS_DATA_FORK)
2364 break;
2365 error = xfs_da3_swap_lastblock(args, &dead_blkno,
2366 &dead_buf);
2367 if (error)
2368 break;
2369 } else {
2370 break;
2371 }
2372 }
2373 xfs_trans_binval(tp, dead_buf);
2374 return error;
2375}
2376
2377/*
2378 * See if the mapping(s) for this btree block are valid, i.e.
2379 * don't contain holes, are logically contiguous, and cover the whole range.
2380 */
2381STATIC int
2382xfs_da_map_covers_blocks(
2383 int nmap,
2384 xfs_bmbt_irec_t *mapp,
2385 xfs_dablk_t bno,
2386 int count)
2387{
2388 int i;
2389 xfs_fileoff_t off;
2390
2391 for (i = 0, off = bno; i < nmap; i++) {
2392 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2393 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2394 return 0;
2395 }
2396 if (off != mapp[i].br_startoff) {
2397 return 0;
2398 }
2399 off += mapp[i].br_blockcount;
2400 }
2401 return off == bno + count;
2402}
2403
2404/*
2405 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
2406 *
2407 * For the single map case, it is assumed that the caller has provided a pointer
2408 * to a valid xfs_buf_map. For the multiple map case, this function will
2409 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
2410 * map pointer with the allocated map.
2411 */
2412static int
2413xfs_buf_map_from_irec(
2414 struct xfs_mount *mp,
2415 struct xfs_buf_map **mapp,
2416 int *nmaps,
2417 struct xfs_bmbt_irec *irecs,
2418 int nirecs)
2419{
2420 struct xfs_buf_map *map;
2421 int i;
2422
2423 ASSERT(*nmaps == 1);
2424 ASSERT(nirecs >= 1);
2425
2426 if (nirecs > 1) {
2427 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map),
2428 KM_SLEEP | KM_NOFS);
2429 if (!map)
2430 return -ENOMEM;
2431 *mapp = map;
2432 }
2433
2434 *nmaps = nirecs;
2435 map = *mapp;
2436 for (i = 0; i < *nmaps; i++) {
2437 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
2438 irecs[i].br_startblock != HOLESTARTBLOCK);
2439 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2440 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2441 }
2442 return 0;
2443}
2444
2445/*
2446 * Map the block we are given ready for reading. There are three possible return
2447 * values:
2448 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
2449 * caller knows not to execute a subsequent read.
2450 * 0 - if we mapped the block successfully
2451 * >0 - positive error number if there was an error.
2452 */
2453static int
2454xfs_dabuf_map(
2455 struct xfs_inode *dp,
2456 xfs_dablk_t bno,
2457 xfs_daddr_t mappedbno,
2458 int whichfork,
2459 struct xfs_buf_map **map,
2460 int *nmaps)
2461{
2462 struct xfs_mount *mp = dp->i_mount;
2463 int nfsb;
2464 int error = 0;
2465 struct xfs_bmbt_irec irec;
2466 struct xfs_bmbt_irec *irecs = &irec;
2467 int nirecs;
2468
2469 ASSERT(map && *map);
2470 ASSERT(*nmaps == 1);
2471
2472 if (whichfork == XFS_DATA_FORK)
2473 nfsb = mp->m_dir_geo->fsbcount;
2474 else
2475 nfsb = mp->m_attr_geo->fsbcount;
2476
2477 /*
2478 * Caller doesn't have a mapping. -2 means don't complain
2479 * if we land in a hole.
2480 */
2481 if (mappedbno == -1 || mappedbno == -2) {
2482 /*
2483 * Optimize the one-block case.
2484 */
2485 if (nfsb != 1)
2486 irecs = kmem_zalloc(sizeof(irec) * nfsb,
2487 KM_SLEEP | KM_NOFS);
2488
2489 nirecs = nfsb;
2490 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2491 &nirecs, xfs_bmapi_aflag(whichfork));
2492 if (error)
2493 goto out;
2494 } else {
2495 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2496 irecs->br_startoff = (xfs_fileoff_t)bno;
2497 irecs->br_blockcount = nfsb;
2498 irecs->br_state = 0;
2499 nirecs = 1;
2500 }
2501
2502 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2503 error = mappedbno == -2 ? -1 : -EFSCORRUPTED;
2504 if (unlikely(error == -EFSCORRUPTED)) {
2505 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2506 int i;
2507 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2508 __func__, (long long)bno,
2509 (long long)dp->i_ino);
2510 for (i = 0; i < *nmaps; i++) {
2511 xfs_alert(mp,
2512"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2513 i,
2514 (long long)irecs[i].br_startoff,
2515 (long long)irecs[i].br_startblock,
2516 (long long)irecs[i].br_blockcount,
2517 irecs[i].br_state);
2518 }
2519 }
2520 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2521 XFS_ERRLEVEL_LOW, mp);
2522 }
2523 goto out;
2524 }
2525 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2526out:
2527 if (irecs != &irec)
2528 kmem_free(irecs);
2529 return error;
2530}
2531
2532/*
2533 * Get a buffer for the dir/attr block.
2534 */
2535int
2536xfs_da_get_buf(
2537 struct xfs_trans *trans,
2538 struct xfs_inode *dp,
2539 xfs_dablk_t bno,
2540 xfs_daddr_t mappedbno,
2541 struct xfs_buf **bpp,
2542 int whichfork)
2543{
2544 struct xfs_buf *bp;
2545 struct xfs_buf_map map;
2546 struct xfs_buf_map *mapp;
2547 int nmap;
2548 int error;
2549
2550 *bpp = NULL;
2551 mapp = &map;
2552 nmap = 1;
2553 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2554 &mapp, &nmap);
2555 if (error) {
2556 /* mapping a hole is not an error, but we don't continue */
2557 if (error == -1)
2558 error = 0;
2559 goto out_free;
2560 }
2561
2562 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2563 mapp, nmap, 0);
2564 error = bp ? bp->b_error : -EIO;
2565 if (error) {
2566 xfs_trans_brelse(trans, bp);
2567 goto out_free;
2568 }
2569
2570 *bpp = bp;
2571
2572out_free:
2573 if (mapp != &map)
2574 kmem_free(mapp);
2575
2576 return error;
2577}
2578
2579/*
2580 * Get a buffer for the dir/attr block, fill in the contents.
2581 */
2582int
2583xfs_da_read_buf(
2584 struct xfs_trans *trans,
2585 struct xfs_inode *dp,
2586 xfs_dablk_t bno,
2587 xfs_daddr_t mappedbno,
2588 struct xfs_buf **bpp,
2589 int whichfork,
2590 const struct xfs_buf_ops *ops)
2591{
2592 struct xfs_buf *bp;
2593 struct xfs_buf_map map;
2594 struct xfs_buf_map *mapp;
2595 int nmap;
2596 int error;
2597
2598 *bpp = NULL;
2599 mapp = &map;
2600 nmap = 1;
2601 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2602 &mapp, &nmap);
2603 if (error) {
2604 /* mapping a hole is not an error, but we don't continue */
2605 if (error == -1)
2606 error = 0;
2607 goto out_free;
2608 }
2609
2610 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2611 dp->i_mount->m_ddev_targp,
2612 mapp, nmap, 0, &bp, ops);
2613 if (error)
2614 goto out_free;
2615
2616 if (whichfork == XFS_ATTR_FORK)
2617 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2618 else
2619 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2620 *bpp = bp;
2621out_free:
2622 if (mapp != &map)
2623 kmem_free(mapp);
2624
2625 return error;
2626}
2627
2628/*
2629 * Readahead the dir/attr block.
2630 */
2631xfs_daddr_t
2632xfs_da_reada_buf(
2633 struct xfs_inode *dp,
2634 xfs_dablk_t bno,
2635 xfs_daddr_t mappedbno,
2636 int whichfork,
2637 const struct xfs_buf_ops *ops)
2638{
2639 struct xfs_buf_map map;
2640 struct xfs_buf_map *mapp;
2641 int nmap;
2642 int error;
2643
2644 mapp = &map;
2645 nmap = 1;
2646 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2647 &mapp, &nmap);
2648 if (error) {
2649 /* mapping a hole is not an error, but we don't continue */
2650 if (error == -1)
2651 error = 0;
2652 goto out_free;
2653 }
2654
2655 mappedbno = mapp[0].bm_bn;
2656 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2657
2658out_free:
2659 if (mapp != &map)
2660 kmem_free(mapp);
2661
2662 if (error)
2663 return -1;
2664 return mappedbno;
2665}
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-08 20:40:49 -0500