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1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
4 * All Rights Reserved.
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19#include "xfs.h"
20#include "xfs_fs.h"
21#include "xfs_shared.h"
22#include "xfs_format.h"
23#include "xfs_log_format.h"
24#include "xfs_trans_resv.h"
25#include "xfs_bit.h"
26#include "xfs_mount.h"
27#include "xfs_da_format.h"
28#include "xfs_da_btree.h"
29#include "xfs_dir2.h"
30#include "xfs_dir2_priv.h"
31#include "xfs_inode.h"
32#include "xfs_trans.h"
33#include "xfs_inode_item.h"
34#include "xfs_alloc.h"
35#include "xfs_bmap.h"
36#include "xfs_attr.h"
37#include "xfs_attr_leaf.h"
38#include "xfs_error.h"
39#include "xfs_trace.h"
40#include "xfs_cksum.h"
41#include "xfs_buf_item.h"
42#include "xfs_log.h"
43
44/*
45 * xfs_da_btree.c
46 *
47 * Routines to implement directories as Btrees of hashed names.
48 */
49
50/*========================================================================
51 * Function prototypes for the kernel.
52 *========================================================================*/
53
54/*
55 * Routines used for growing the Btree.
56 */
57STATIC int xfs_da3_root_split(xfs_da_state_t *state,
58 xfs_da_state_blk_t *existing_root,
59 xfs_da_state_blk_t *new_child);
60STATIC int xfs_da3_node_split(xfs_da_state_t *state,
61 xfs_da_state_blk_t *existing_blk,
62 xfs_da_state_blk_t *split_blk,
63 xfs_da_state_blk_t *blk_to_add,
64 int treelevel,
65 int *result);
66STATIC void xfs_da3_node_rebalance(xfs_da_state_t *state,
67 xfs_da_state_blk_t *node_blk_1,
68 xfs_da_state_blk_t *node_blk_2);
69STATIC void xfs_da3_node_add(xfs_da_state_t *state,
70 xfs_da_state_blk_t *old_node_blk,
71 xfs_da_state_blk_t *new_node_blk);
72
73/*
74 * Routines used for shrinking the Btree.
75 */
76STATIC int xfs_da3_root_join(xfs_da_state_t *state,
77 xfs_da_state_blk_t *root_blk);
78STATIC int xfs_da3_node_toosmall(xfs_da_state_t *state, int *retval);
79STATIC void xfs_da3_node_remove(xfs_da_state_t *state,
80 xfs_da_state_blk_t *drop_blk);
81STATIC void xfs_da3_node_unbalance(xfs_da_state_t *state,
82 xfs_da_state_blk_t *src_node_blk,
83 xfs_da_state_blk_t *dst_node_blk);
84
85/*
86 * Utility routines.
87 */
88STATIC int xfs_da3_blk_unlink(xfs_da_state_t *state,
89 xfs_da_state_blk_t *drop_blk,
90 xfs_da_state_blk_t *save_blk);
91
92
93kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
94
95/*
96 * Allocate a dir-state structure.
97 * We don't put them on the stack since they're large.
98 */
99xfs_da_state_t *
100xfs_da_state_alloc(void)
101{
102 return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
103}
104
105/*
106 * Kill the altpath contents of a da-state structure.
107 */
108STATIC void
109xfs_da_state_kill_altpath(xfs_da_state_t *state)
110{
111 int i;
112
113 for (i = 0; i < state->altpath.active; i++)
114 state->altpath.blk[i].bp = NULL;
115 state->altpath.active = 0;
116}
117
118/*
119 * Free a da-state structure.
120 */
121void
122xfs_da_state_free(xfs_da_state_t *state)
123{
124 xfs_da_state_kill_altpath(state);
125#ifdef DEBUG
126 memset((char *)state, 0, sizeof(*state));
127#endif /* DEBUG */
128 kmem_zone_free(xfs_da_state_zone, state);
129}
130
131static xfs_failaddr_t
132xfs_da3_node_verify(
133 struct xfs_buf *bp)
134{
135 struct xfs_mount *mp = bp->b_target->bt_mount;
136 struct xfs_da_intnode *hdr = bp->b_addr;
137 struct xfs_da3_icnode_hdr ichdr;
138 const struct xfs_dir_ops *ops;
139
140 ops = xfs_dir_get_ops(mp, NULL);
141
142 ops->node_hdr_from_disk(&ichdr, hdr);
143
144 if (xfs_sb_version_hascrc(&mp->m_sb)) {
145 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
146
147 if (ichdr.magic != XFS_DA3_NODE_MAGIC)
148 return __this_address;
149
150 if (!uuid_equal(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid))
151 return __this_address;
152 if (be64_to_cpu(hdr3->info.blkno) != bp->b_bn)
153 return __this_address;
154 if (!xfs_log_check_lsn(mp, be64_to_cpu(hdr3->info.lsn)))
155 return __this_address;
156 } else {
157 if (ichdr.magic != XFS_DA_NODE_MAGIC)
158 return __this_address;
159 }
160 if (ichdr.level == 0)
161 return __this_address;
162 if (ichdr.level > XFS_DA_NODE_MAXDEPTH)
163 return __this_address;
164 if (ichdr.count == 0)
165 return __this_address;
166
167 /*
168 * we don't know if the node is for and attribute or directory tree,
169 * so only fail if the count is outside both bounds
170 */
171 if (ichdr.count > mp->m_dir_geo->node_ents &&
172 ichdr.count > mp->m_attr_geo->node_ents)
173 return __this_address;
174
175 /* XXX: hash order check? */
176
177 return NULL;
178}
179
180static void
181xfs_da3_node_write_verify(
182 struct xfs_buf *bp)
183{
184 struct xfs_mount *mp = bp->b_target->bt_mount;
185 struct xfs_buf_log_item *bip = bp->b_log_item;
186 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
187 xfs_failaddr_t fa;
188
189 fa = xfs_da3_node_verify(bp);
190 if (fa) {
191 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
192 return;
193 }
194
195 if (!xfs_sb_version_hascrc(&mp->m_sb))
196 return;
197
198 if (bip)
199 hdr3->info.lsn = cpu_to_be64(bip->bli_item.li_lsn);
200
201 xfs_buf_update_cksum(bp, XFS_DA3_NODE_CRC_OFF);
202}
203
204/*
205 * leaf/node format detection on trees is sketchy, so a node read can be done on
206 * leaf level blocks when detection identifies the tree as a node format tree
207 * incorrectly. In this case, we need to swap the verifier to match the correct
208 * format of the block being read.
209 */
210static void
211xfs_da3_node_read_verify(
212 struct xfs_buf *bp)
213{
214 struct xfs_da_blkinfo *info = bp->b_addr;
215 xfs_failaddr_t fa;
216
217 switch (be16_to_cpu(info->magic)) {
218 case XFS_DA3_NODE_MAGIC:
219 if (!xfs_buf_verify_cksum(bp, XFS_DA3_NODE_CRC_OFF)) {
220 xfs_verifier_error(bp, -EFSBADCRC,
221 __this_address);
222 break;
223 }
224 /* fall through */
225 case XFS_DA_NODE_MAGIC:
226 fa = xfs_da3_node_verify(bp);
227 if (fa)
228 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
229 return;
230 case XFS_ATTR_LEAF_MAGIC:
231 case XFS_ATTR3_LEAF_MAGIC:
232 bp->b_ops = &xfs_attr3_leaf_buf_ops;
233 bp->b_ops->verify_read(bp);
234 return;
235 case XFS_DIR2_LEAFN_MAGIC:
236 case XFS_DIR3_LEAFN_MAGIC:
237 bp->b_ops = &xfs_dir3_leafn_buf_ops;
238 bp->b_ops->verify_read(bp);
239 return;
240 default:
241 xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
242 break;
243 }
244}
245
246/* Verify the structure of a da3 block. */
247static xfs_failaddr_t
248xfs_da3_node_verify_struct(
249 struct xfs_buf *bp)
250{
251 struct xfs_da_blkinfo *info = bp->b_addr;
252
253 switch (be16_to_cpu(info->magic)) {
254 case XFS_DA3_NODE_MAGIC:
255 case XFS_DA_NODE_MAGIC:
256 return xfs_da3_node_verify(bp);
257 case XFS_ATTR_LEAF_MAGIC:
258 case XFS_ATTR3_LEAF_MAGIC:
259 bp->b_ops = &xfs_attr3_leaf_buf_ops;
260 return bp->b_ops->verify_struct(bp);
261 case XFS_DIR2_LEAFN_MAGIC:
262 case XFS_DIR3_LEAFN_MAGIC:
263 bp->b_ops = &xfs_dir3_leafn_buf_ops;
264 return bp->b_ops->verify_struct(bp);
265 default:
266 return __this_address;
267 }
268}
269
270const struct xfs_buf_ops xfs_da3_node_buf_ops = {
271 .name = "xfs_da3_node",
272 .verify_read = xfs_da3_node_read_verify,
273 .verify_write = xfs_da3_node_write_verify,
274 .verify_struct = xfs_da3_node_verify_struct,
275};
276
277int
278xfs_da3_node_read(
279 struct xfs_trans *tp,
280 struct xfs_inode *dp,
281 xfs_dablk_t bno,
282 xfs_daddr_t mappedbno,
283 struct xfs_buf **bpp,
284 int which_fork)
285{
286 int err;
287
288 err = xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
289 which_fork, &xfs_da3_node_buf_ops);
290 if (!err && tp && *bpp) {
291 struct xfs_da_blkinfo *info = (*bpp)->b_addr;
292 int type;
293
294 switch (be16_to_cpu(info->magic)) {
295 case XFS_DA_NODE_MAGIC:
296 case XFS_DA3_NODE_MAGIC:
297 type = XFS_BLFT_DA_NODE_BUF;
298 break;
299 case XFS_ATTR_LEAF_MAGIC:
300 case XFS_ATTR3_LEAF_MAGIC:
301 type = XFS_BLFT_ATTR_LEAF_BUF;
302 break;
303 case XFS_DIR2_LEAFN_MAGIC:
304 case XFS_DIR3_LEAFN_MAGIC:
305 type = XFS_BLFT_DIR_LEAFN_BUF;
306 break;
307 default:
308 type = 0;
309 ASSERT(0);
310 break;
311 }
312 xfs_trans_buf_set_type(tp, *bpp, type);
313 }
314 return err;
315}
316
317/*========================================================================
318 * Routines used for growing the Btree.
319 *========================================================================*/
320
321/*
322 * Create the initial contents of an intermediate node.
323 */
324int
325xfs_da3_node_create(
326 struct xfs_da_args *args,
327 xfs_dablk_t blkno,
328 int level,
329 struct xfs_buf **bpp,
330 int whichfork)
331{
332 struct xfs_da_intnode *node;
333 struct xfs_trans *tp = args->trans;
334 struct xfs_mount *mp = tp->t_mountp;
335 struct xfs_da3_icnode_hdr ichdr = {0};
336 struct xfs_buf *bp;
337 int error;
338 struct xfs_inode *dp = args->dp;
339
340 trace_xfs_da_node_create(args);
341 ASSERT(level <= XFS_DA_NODE_MAXDEPTH);
342
343 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, whichfork);
344 if (error)
345 return error;
346 bp->b_ops = &xfs_da3_node_buf_ops;
347 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
348 node = bp->b_addr;
349
350 if (xfs_sb_version_hascrc(&mp->m_sb)) {
351 struct xfs_da3_node_hdr *hdr3 = bp->b_addr;
352
353 memset(hdr3, 0, sizeof(struct xfs_da3_node_hdr));
354 ichdr.magic = XFS_DA3_NODE_MAGIC;
355 hdr3->info.blkno = cpu_to_be64(bp->b_bn);
356 hdr3->info.owner = cpu_to_be64(args->dp->i_ino);
357 uuid_copy(&hdr3->info.uuid, &mp->m_sb.sb_meta_uuid);
358 } else {
359 ichdr.magic = XFS_DA_NODE_MAGIC;
360 }
361 ichdr.level = level;
362
363 dp->d_ops->node_hdr_to_disk(node, &ichdr);
364 xfs_trans_log_buf(tp, bp,
365 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
366
367 *bpp = bp;
368 return 0;
369}
370
371/*
372 * Split a leaf node, rebalance, then possibly split
373 * intermediate nodes, rebalance, etc.
374 */
375int /* error */
376xfs_da3_split(
377 struct xfs_da_state *state)
378{
379 struct xfs_da_state_blk *oldblk;
380 struct xfs_da_state_blk *newblk;
381 struct xfs_da_state_blk *addblk;
382 struct xfs_da_intnode *node;
383 int max;
384 int action = 0;
385 int error;
386 int i;
387
388 trace_xfs_da_split(state->args);
389
390 /*
391 * Walk back up the tree splitting/inserting/adjusting as necessary.
392 * If we need to insert and there isn't room, split the node, then
393 * decide which fragment to insert the new block from below into.
394 * Note that we may split the root this way, but we need more fixup.
395 */
396 max = state->path.active - 1;
397 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
398 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
399 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
400
401 addblk = &state->path.blk[max]; /* initial dummy value */
402 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
403 oldblk = &state->path.blk[i];
404 newblk = &state->altpath.blk[i];
405
406 /*
407 * If a leaf node then
408 * Allocate a new leaf node, then rebalance across them.
409 * else if an intermediate node then
410 * We split on the last layer, must we split the node?
411 */
412 switch (oldblk->magic) {
413 case XFS_ATTR_LEAF_MAGIC:
414 error = xfs_attr3_leaf_split(state, oldblk, newblk);
415 if ((error != 0) && (error != -ENOSPC)) {
416 return error; /* GROT: attr is inconsistent */
417 }
418 if (!error) {
419 addblk = newblk;
420 break;
421 }
422 /*
423 * Entry wouldn't fit, split the leaf again. The new
424 * extrablk will be consumed by xfs_da3_node_split if
425 * the node is split.
426 */
427 state->extravalid = 1;
428 if (state->inleaf) {
429 state->extraafter = 0; /* before newblk */
430 trace_xfs_attr_leaf_split_before(state->args);
431 error = xfs_attr3_leaf_split(state, oldblk,
432 &state->extrablk);
433 } else {
434 state->extraafter = 1; /* after newblk */
435 trace_xfs_attr_leaf_split_after(state->args);
436 error = xfs_attr3_leaf_split(state, newblk,
437 &state->extrablk);
438 }
439 if (error)
440 return error; /* GROT: attr inconsistent */
441 addblk = newblk;
442 break;
443 case XFS_DIR2_LEAFN_MAGIC:
444 error = xfs_dir2_leafn_split(state, oldblk, newblk);
445 if (error)
446 return error;
447 addblk = newblk;
448 break;
449 case XFS_DA_NODE_MAGIC:
450 error = xfs_da3_node_split(state, oldblk, newblk, addblk,
451 max - i, &action);
452 addblk->bp = NULL;
453 if (error)
454 return error; /* GROT: dir is inconsistent */
455 /*
456 * Record the newly split block for the next time thru?
457 */
458 if (action)
459 addblk = newblk;
460 else
461 addblk = NULL;
462 break;
463 }
464
465 /*
466 * Update the btree to show the new hashval for this child.
467 */
468 xfs_da3_fixhashpath(state, &state->path);
469 }
470 if (!addblk)
471 return 0;
472
473 /*
474 * xfs_da3_node_split() should have consumed any extra blocks we added
475 * during a double leaf split in the attr fork. This is guaranteed as
476 * we can't be here if the attr fork only has a single leaf block.
477 */
478 ASSERT(state->extravalid == 0 ||
479 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
480
481 /*
482 * Split the root node.
483 */
484 ASSERT(state->path.active == 0);
485 oldblk = &state->path.blk[0];
486 error = xfs_da3_root_split(state, oldblk, addblk);
487 if (error) {
488 addblk->bp = NULL;
489 return error; /* GROT: dir is inconsistent */
490 }
491
492 /*
493 * Update pointers to the node which used to be block 0 and just got
494 * bumped because of the addition of a new root node. Note that the
495 * original block 0 could be at any position in the list of blocks in
496 * the tree.
497 *
498 * Note: the magic numbers and sibling pointers are in the same physical
499 * place for both v2 and v3 headers (by design). Hence it doesn't matter
500 * which version of the xfs_da_intnode structure we use here as the
501 * result will be the same using either structure.
502 */
503 node = oldblk->bp->b_addr;
504 if (node->hdr.info.forw) {
505 ASSERT(be32_to_cpu(node->hdr.info.forw) == addblk->blkno);
506 node = addblk->bp->b_addr;
507 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
508 xfs_trans_log_buf(state->args->trans, addblk->bp,
509 XFS_DA_LOGRANGE(node, &node->hdr.info,
510 sizeof(node->hdr.info)));
511 }
512 node = oldblk->bp->b_addr;
513 if (node->hdr.info.back) {
514 ASSERT(be32_to_cpu(node->hdr.info.back) == addblk->blkno);
515 node = addblk->bp->b_addr;
516 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
517 xfs_trans_log_buf(state->args->trans, addblk->bp,
518 XFS_DA_LOGRANGE(node, &node->hdr.info,
519 sizeof(node->hdr.info)));
520 }
521 addblk->bp = NULL;
522 return 0;
523}
524
525/*
526 * Split the root. We have to create a new root and point to the two
527 * parts (the split old root) that we just created. Copy block zero to
528 * the EOF, extending the inode in process.
529 */
530STATIC int /* error */
531xfs_da3_root_split(
532 struct xfs_da_state *state,
533 struct xfs_da_state_blk *blk1,
534 struct xfs_da_state_blk *blk2)
535{
536 struct xfs_da_intnode *node;
537 struct xfs_da_intnode *oldroot;
538 struct xfs_da_node_entry *btree;
539 struct xfs_da3_icnode_hdr nodehdr;
540 struct xfs_da_args *args;
541 struct xfs_buf *bp;
542 struct xfs_inode *dp;
543 struct xfs_trans *tp;
544 struct xfs_dir2_leaf *leaf;
545 xfs_dablk_t blkno;
546 int level;
547 int error;
548 int size;
549
550 trace_xfs_da_root_split(state->args);
551
552 /*
553 * Copy the existing (incorrect) block from the root node position
554 * to a free space somewhere.
555 */
556 args = state->args;
557 error = xfs_da_grow_inode(args, &blkno);
558 if (error)
559 return error;
560
561 dp = args->dp;
562 tp = args->trans;
563 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
564 if (error)
565 return error;
566 node = bp->b_addr;
567 oldroot = blk1->bp->b_addr;
568 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
569 oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
570 struct xfs_da3_icnode_hdr icnodehdr;
571
572 dp->d_ops->node_hdr_from_disk(&icnodehdr, oldroot);
573 btree = dp->d_ops->node_tree_p(oldroot);
574 size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
575 level = icnodehdr.level;
576
577 /*
578 * we are about to copy oldroot to bp, so set up the type
579 * of bp while we know exactly what it will be.
580 */
581 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
582 } else {
583 struct xfs_dir3_icleaf_hdr leafhdr;
584 struct xfs_dir2_leaf_entry *ents;
585
586 leaf = (xfs_dir2_leaf_t *)oldroot;
587 dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
588 ents = dp->d_ops->leaf_ents_p(leaf);
589
590 ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
591 leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
592 size = (int)((char *)&ents[leafhdr.count] - (char *)leaf);
593 level = 0;
594
595 /*
596 * we are about to copy oldroot to bp, so set up the type
597 * of bp while we know exactly what it will be.
598 */
599 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
600 }
601
602 /*
603 * we can copy most of the information in the node from one block to
604 * another, but for CRC enabled headers we have to make sure that the
605 * block specific identifiers are kept intact. We update the buffer
606 * directly for this.
607 */
608 memcpy(node, oldroot, size);
609 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
610 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
611 struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
612
613 node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
614 }
615 xfs_trans_log_buf(tp, bp, 0, size - 1);
616
617 bp->b_ops = blk1->bp->b_ops;
618 xfs_trans_buf_copy_type(bp, blk1->bp);
619 blk1->bp = bp;
620 blk1->blkno = blkno;
621
622 /*
623 * Set up the new root node.
624 */
625 error = xfs_da3_node_create(args,
626 (args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
627 level + 1, &bp, args->whichfork);
628 if (error)
629 return error;
630
631 node = bp->b_addr;
632 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
633 btree = dp->d_ops->node_tree_p(node);
634 btree[0].hashval = cpu_to_be32(blk1->hashval);
635 btree[0].before = cpu_to_be32(blk1->blkno);
636 btree[1].hashval = cpu_to_be32(blk2->hashval);
637 btree[1].before = cpu_to_be32(blk2->blkno);
638 nodehdr.count = 2;
639 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
640
641#ifdef DEBUG
642 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
643 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
644 ASSERT(blk1->blkno >= args->geo->leafblk &&
645 blk1->blkno < args->geo->freeblk);
646 ASSERT(blk2->blkno >= args->geo->leafblk &&
647 blk2->blkno < args->geo->freeblk);
648 }
649#endif
650
651 /* Header is already logged by xfs_da_node_create */
652 xfs_trans_log_buf(tp, bp,
653 XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
654
655 return 0;
656}
657
658/*
659 * Split the node, rebalance, then add the new entry.
660 */
661STATIC int /* error */
662xfs_da3_node_split(
663 struct xfs_da_state *state,
664 struct xfs_da_state_blk *oldblk,
665 struct xfs_da_state_blk *newblk,
666 struct xfs_da_state_blk *addblk,
667 int treelevel,
668 int *result)
669{
670 struct xfs_da_intnode *node;
671 struct xfs_da3_icnode_hdr nodehdr;
672 xfs_dablk_t blkno;
673 int newcount;
674 int error;
675 int useextra;
676 struct xfs_inode *dp = state->args->dp;
677
678 trace_xfs_da_node_split(state->args);
679
680 node = oldblk->bp->b_addr;
681 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
682
683 /*
684 * With V2 dirs the extra block is data or freespace.
685 */
686 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
687 newcount = 1 + useextra;
688 /*
689 * Do we have to split the node?
690 */
691 if (nodehdr.count + newcount > state->args->geo->node_ents) {
692 /*
693 * Allocate a new node, add to the doubly linked chain of
694 * nodes, then move some of our excess entries into it.
695 */
696 error = xfs_da_grow_inode(state->args, &blkno);
697 if (error)
698 return error; /* GROT: dir is inconsistent */
699
700 error = xfs_da3_node_create(state->args, blkno, treelevel,
701 &newblk->bp, state->args->whichfork);
702 if (error)
703 return error; /* GROT: dir is inconsistent */
704 newblk->blkno = blkno;
705 newblk->magic = XFS_DA_NODE_MAGIC;
706 xfs_da3_node_rebalance(state, oldblk, newblk);
707 error = xfs_da3_blk_link(state, oldblk, newblk);
708 if (error)
709 return error;
710 *result = 1;
711 } else {
712 *result = 0;
713 }
714
715 /*
716 * Insert the new entry(s) into the correct block
717 * (updating last hashval in the process).
718 *
719 * xfs_da3_node_add() inserts BEFORE the given index,
720 * and as a result of using node_lookup_int() we always
721 * point to a valid entry (not after one), but a split
722 * operation always results in a new block whose hashvals
723 * FOLLOW the current block.
724 *
725 * If we had double-split op below us, then add the extra block too.
726 */
727 node = oldblk->bp->b_addr;
728 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
729 if (oldblk->index <= nodehdr.count) {
730 oldblk->index++;
731 xfs_da3_node_add(state, oldblk, addblk);
732 if (useextra) {
733 if (state->extraafter)
734 oldblk->index++;
735 xfs_da3_node_add(state, oldblk, &state->extrablk);
736 state->extravalid = 0;
737 }
738 } else {
739 newblk->index++;
740 xfs_da3_node_add(state, newblk, addblk);
741 if (useextra) {
742 if (state->extraafter)
743 newblk->index++;
744 xfs_da3_node_add(state, newblk, &state->extrablk);
745 state->extravalid = 0;
746 }
747 }
748
749 return 0;
750}
751
752/*
753 * Balance the btree elements between two intermediate nodes,
754 * usually one full and one empty.
755 *
756 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
757 */
758STATIC void
759xfs_da3_node_rebalance(
760 struct xfs_da_state *state,
761 struct xfs_da_state_blk *blk1,
762 struct xfs_da_state_blk *blk2)
763{
764 struct xfs_da_intnode *node1;
765 struct xfs_da_intnode *node2;
766 struct xfs_da_intnode *tmpnode;
767 struct xfs_da_node_entry *btree1;
768 struct xfs_da_node_entry *btree2;
769 struct xfs_da_node_entry *btree_s;
770 struct xfs_da_node_entry *btree_d;
771 struct xfs_da3_icnode_hdr nodehdr1;
772 struct xfs_da3_icnode_hdr nodehdr2;
773 struct xfs_trans *tp;
774 int count;
775 int tmp;
776 int swap = 0;
777 struct xfs_inode *dp = state->args->dp;
778
779 trace_xfs_da_node_rebalance(state->args);
780
781 node1 = blk1->bp->b_addr;
782 node2 = blk2->bp->b_addr;
783 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
784 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
785 btree1 = dp->d_ops->node_tree_p(node1);
786 btree2 = dp->d_ops->node_tree_p(node2);
787
788 /*
789 * Figure out how many entries need to move, and in which direction.
790 * Swap the nodes around if that makes it simpler.
791 */
792 if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
793 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
794 (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
795 be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
796 tmpnode = node1;
797 node1 = node2;
798 node2 = tmpnode;
799 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
800 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
801 btree1 = dp->d_ops->node_tree_p(node1);
802 btree2 = dp->d_ops->node_tree_p(node2);
803 swap = 1;
804 }
805
806 count = (nodehdr1.count - nodehdr2.count) / 2;
807 if (count == 0)
808 return;
809 tp = state->args->trans;
810 /*
811 * Two cases: high-to-low and low-to-high.
812 */
813 if (count > 0) {
814 /*
815 * Move elements in node2 up to make a hole.
816 */
817 tmp = nodehdr2.count;
818 if (tmp > 0) {
819 tmp *= (uint)sizeof(xfs_da_node_entry_t);
820 btree_s = &btree2[0];
821 btree_d = &btree2[count];
822 memmove(btree_d, btree_s, tmp);
823 }
824
825 /*
826 * Move the req'd B-tree elements from high in node1 to
827 * low in node2.
828 */
829 nodehdr2.count += count;
830 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
831 btree_s = &btree1[nodehdr1.count - count];
832 btree_d = &btree2[0];
833 memcpy(btree_d, btree_s, tmp);
834 nodehdr1.count -= count;
835 } else {
836 /*
837 * Move the req'd B-tree elements from low in node2 to
838 * high in node1.
839 */
840 count = -count;
841 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
842 btree_s = &btree2[0];
843 btree_d = &btree1[nodehdr1.count];
844 memcpy(btree_d, btree_s, tmp);
845 nodehdr1.count += count;
846
847 xfs_trans_log_buf(tp, blk1->bp,
848 XFS_DA_LOGRANGE(node1, btree_d, tmp));
849
850 /*
851 * Move elements in node2 down to fill the hole.
852 */
853 tmp = nodehdr2.count - count;
854 tmp *= (uint)sizeof(xfs_da_node_entry_t);
855 btree_s = &btree2[count];
856 btree_d = &btree2[0];
857 memmove(btree_d, btree_s, tmp);
858 nodehdr2.count -= count;
859 }
860
861 /*
862 * Log header of node 1 and all current bits of node 2.
863 */
864 dp->d_ops->node_hdr_to_disk(node1, &nodehdr1);
865 xfs_trans_log_buf(tp, blk1->bp,
866 XFS_DA_LOGRANGE(node1, &node1->hdr, dp->d_ops->node_hdr_size));
867
868 dp->d_ops->node_hdr_to_disk(node2, &nodehdr2);
869 xfs_trans_log_buf(tp, blk2->bp,
870 XFS_DA_LOGRANGE(node2, &node2->hdr,
871 dp->d_ops->node_hdr_size +
872 (sizeof(btree2[0]) * nodehdr2.count)));
873
874 /*
875 * Record the last hashval from each block for upward propagation.
876 * (note: don't use the swapped node pointers)
877 */
878 if (swap) {
879 node1 = blk1->bp->b_addr;
880 node2 = blk2->bp->b_addr;
881 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
882 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
883 btree1 = dp->d_ops->node_tree_p(node1);
884 btree2 = dp->d_ops->node_tree_p(node2);
885 }
886 blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
887 blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
888
889 /*
890 * Adjust the expected index for insertion.
891 */
892 if (blk1->index >= nodehdr1.count) {
893 blk2->index = blk1->index - nodehdr1.count;
894 blk1->index = nodehdr1.count + 1; /* make it invalid */
895 }
896}
897
898/*
899 * Add a new entry to an intermediate node.
900 */
901STATIC void
902xfs_da3_node_add(
903 struct xfs_da_state *state,
904 struct xfs_da_state_blk *oldblk,
905 struct xfs_da_state_blk *newblk)
906{
907 struct xfs_da_intnode *node;
908 struct xfs_da3_icnode_hdr nodehdr;
909 struct xfs_da_node_entry *btree;
910 int tmp;
911 struct xfs_inode *dp = state->args->dp;
912
913 trace_xfs_da_node_add(state->args);
914
915 node = oldblk->bp->b_addr;
916 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
917 btree = dp->d_ops->node_tree_p(node);
918
919 ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
920 ASSERT(newblk->blkno != 0);
921 if (state->args->whichfork == XFS_DATA_FORK)
922 ASSERT(newblk->blkno >= state->args->geo->leafblk &&
923 newblk->blkno < state->args->geo->freeblk);
924
925 /*
926 * We may need to make some room before we insert the new node.
927 */
928 tmp = 0;
929 if (oldblk->index < nodehdr.count) {
930 tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
931 memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
932 }
933 btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
934 btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
935 xfs_trans_log_buf(state->args->trans, oldblk->bp,
936 XFS_DA_LOGRANGE(node, &btree[oldblk->index],
937 tmp + sizeof(*btree)));
938
939 nodehdr.count += 1;
940 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
941 xfs_trans_log_buf(state->args->trans, oldblk->bp,
942 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
943
944 /*
945 * Copy the last hash value from the oldblk to propagate upwards.
946 */
947 oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
948}
949
950/*========================================================================
951 * Routines used for shrinking the Btree.
952 *========================================================================*/
953
954/*
955 * Deallocate an empty leaf node, remove it from its parent,
956 * possibly deallocating that block, etc...
957 */
958int
959xfs_da3_join(
960 struct xfs_da_state *state)
961{
962 struct xfs_da_state_blk *drop_blk;
963 struct xfs_da_state_blk *save_blk;
964 int action = 0;
965 int error;
966
967 trace_xfs_da_join(state->args);
968
969 drop_blk = &state->path.blk[ state->path.active-1 ];
970 save_blk = &state->altpath.blk[ state->path.active-1 ];
971 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
972 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
973 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
974
975 /*
976 * Walk back up the tree joining/deallocating as necessary.
977 * When we stop dropping blocks, break out.
978 */
979 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
980 state->path.active--) {
981 /*
982 * See if we can combine the block with a neighbor.
983 * (action == 0) => no options, just leave
984 * (action == 1) => coalesce, then unlink
985 * (action == 2) => block empty, unlink it
986 */
987 switch (drop_blk->magic) {
988 case XFS_ATTR_LEAF_MAGIC:
989 error = xfs_attr3_leaf_toosmall(state, &action);
990 if (error)
991 return error;
992 if (action == 0)
993 return 0;
994 xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
995 break;
996 case XFS_DIR2_LEAFN_MAGIC:
997 error = xfs_dir2_leafn_toosmall(state, &action);
998 if (error)
999 return error;
1000 if (action == 0)
1001 return 0;
1002 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
1003 break;
1004 case XFS_DA_NODE_MAGIC:
1005 /*
1006 * Remove the offending node, fixup hashvals,
1007 * check for a toosmall neighbor.
1008 */
1009 xfs_da3_node_remove(state, drop_blk);
1010 xfs_da3_fixhashpath(state, &state->path);
1011 error = xfs_da3_node_toosmall(state, &action);
1012 if (error)
1013 return error;
1014 if (action == 0)
1015 return 0;
1016 xfs_da3_node_unbalance(state, drop_blk, save_blk);
1017 break;
1018 }
1019 xfs_da3_fixhashpath(state, &state->altpath);
1020 error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
1021 xfs_da_state_kill_altpath(state);
1022 if (error)
1023 return error;
1024 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1025 drop_blk->bp);
1026 drop_blk->bp = NULL;
1027 if (error)
1028 return error;
1029 }
1030 /*
1031 * We joined all the way to the top. If it turns out that
1032 * we only have one entry in the root, make the child block
1033 * the new root.
1034 */
1035 xfs_da3_node_remove(state, drop_blk);
1036 xfs_da3_fixhashpath(state, &state->path);
1037 error = xfs_da3_root_join(state, &state->path.blk[0]);
1038 return error;
1039}
1040
1041#ifdef DEBUG
1042static void
1043xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1044{
1045 __be16 magic = blkinfo->magic;
1046
1047 if (level == 1) {
1048 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1049 magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1050 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1051 magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1052 } else {
1053 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1054 magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1055 }
1056 ASSERT(!blkinfo->forw);
1057 ASSERT(!blkinfo->back);
1058}
1059#else /* !DEBUG */
1060#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1061#endif /* !DEBUG */
1062
1063/*
1064 * We have only one entry in the root. Copy the only remaining child of
1065 * the old root to block 0 as the new root node.
1066 */
1067STATIC int
1068xfs_da3_root_join(
1069 struct xfs_da_state *state,
1070 struct xfs_da_state_blk *root_blk)
1071{
1072 struct xfs_da_intnode *oldroot;
1073 struct xfs_da_args *args;
1074 xfs_dablk_t child;
1075 struct xfs_buf *bp;
1076 struct xfs_da3_icnode_hdr oldroothdr;
1077 struct xfs_da_node_entry *btree;
1078 int error;
1079 struct xfs_inode *dp = state->args->dp;
1080
1081 trace_xfs_da_root_join(state->args);
1082
1083 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1084
1085 args = state->args;
1086 oldroot = root_blk->bp->b_addr;
1087 dp->d_ops->node_hdr_from_disk(&oldroothdr, oldroot);
1088 ASSERT(oldroothdr.forw == 0);
1089 ASSERT(oldroothdr.back == 0);
1090
1091 /*
1092 * If the root has more than one child, then don't do anything.
1093 */
1094 if (oldroothdr.count > 1)
1095 return 0;
1096
1097 /*
1098 * Read in the (only) child block, then copy those bytes into
1099 * the root block's buffer and free the original child block.
1100 */
1101 btree = dp->d_ops->node_tree_p(oldroot);
1102 child = be32_to_cpu(btree[0].before);
1103 ASSERT(child != 0);
1104 error = xfs_da3_node_read(args->trans, dp, child, -1, &bp,
1105 args->whichfork);
1106 if (error)
1107 return error;
1108 xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1109
1110 /*
1111 * This could be copying a leaf back into the root block in the case of
1112 * there only being a single leaf block left in the tree. Hence we have
1113 * to update the b_ops pointer as well to match the buffer type change
1114 * that could occur. For dir3 blocks we also need to update the block
1115 * number in the buffer header.
1116 */
1117 memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1118 root_blk->bp->b_ops = bp->b_ops;
1119 xfs_trans_buf_copy_type(root_blk->bp, bp);
1120 if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1121 struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1122 da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
1123 }
1124 xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1125 args->geo->blksize - 1);
1126 error = xfs_da_shrink_inode(args, child, bp);
1127 return error;
1128}
1129
1130/*
1131 * Check a node block and its neighbors to see if the block should be
1132 * collapsed into one or the other neighbor. Always keep the block
1133 * with the smaller block number.
1134 * If the current block is over 50% full, don't try to join it, return 0.
1135 * If the block is empty, fill in the state structure and return 2.
1136 * If it can be collapsed, fill in the state structure and return 1.
1137 * If nothing can be done, return 0.
1138 */
1139STATIC int
1140xfs_da3_node_toosmall(
1141 struct xfs_da_state *state,
1142 int *action)
1143{
1144 struct xfs_da_intnode *node;
1145 struct xfs_da_state_blk *blk;
1146 struct xfs_da_blkinfo *info;
1147 xfs_dablk_t blkno;
1148 struct xfs_buf *bp;
1149 struct xfs_da3_icnode_hdr nodehdr;
1150 int count;
1151 int forward;
1152 int error;
1153 int retval;
1154 int i;
1155 struct xfs_inode *dp = state->args->dp;
1156
1157 trace_xfs_da_node_toosmall(state->args);
1158
1159 /*
1160 * Check for the degenerate case of the block being over 50% full.
1161 * If so, it's not worth even looking to see if we might be able
1162 * to coalesce with a sibling.
1163 */
1164 blk = &state->path.blk[ state->path.active-1 ];
1165 info = blk->bp->b_addr;
1166 node = (xfs_da_intnode_t *)info;
1167 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1168 if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1169 *action = 0; /* blk over 50%, don't try to join */
1170 return 0; /* blk over 50%, don't try to join */
1171 }
1172
1173 /*
1174 * Check for the degenerate case of the block being empty.
1175 * If the block is empty, we'll simply delete it, no need to
1176 * coalesce it with a sibling block. We choose (arbitrarily)
1177 * to merge with the forward block unless it is NULL.
1178 */
1179 if (nodehdr.count == 0) {
1180 /*
1181 * Make altpath point to the block we want to keep and
1182 * path point to the block we want to drop (this one).
1183 */
1184 forward = (info->forw != 0);
1185 memcpy(&state->altpath, &state->path, sizeof(state->path));
1186 error = xfs_da3_path_shift(state, &state->altpath, forward,
1187 0, &retval);
1188 if (error)
1189 return error;
1190 if (retval) {
1191 *action = 0;
1192 } else {
1193 *action = 2;
1194 }
1195 return 0;
1196 }
1197
1198 /*
1199 * Examine each sibling block to see if we can coalesce with
1200 * at least 25% free space to spare. We need to figure out
1201 * whether to merge with the forward or the backward block.
1202 * We prefer coalescing with the lower numbered sibling so as
1203 * to shrink a directory over time.
1204 */
1205 count = state->args->geo->node_ents;
1206 count -= state->args->geo->node_ents >> 2;
1207 count -= nodehdr.count;
1208
1209 /* start with smaller blk num */
1210 forward = nodehdr.forw < nodehdr.back;
1211 for (i = 0; i < 2; forward = !forward, i++) {
1212 struct xfs_da3_icnode_hdr thdr;
1213 if (forward)
1214 blkno = nodehdr.forw;
1215 else
1216 blkno = nodehdr.back;
1217 if (blkno == 0)
1218 continue;
1219 error = xfs_da3_node_read(state->args->trans, dp,
1220 blkno, -1, &bp, state->args->whichfork);
1221 if (error)
1222 return error;
1223
1224 node = bp->b_addr;
1225 dp->d_ops->node_hdr_from_disk(&thdr, node);
1226 xfs_trans_brelse(state->args->trans, bp);
1227
1228 if (count - thdr.count >= 0)
1229 break; /* fits with at least 25% to spare */
1230 }
1231 if (i >= 2) {
1232 *action = 0;
1233 return 0;
1234 }
1235
1236 /*
1237 * Make altpath point to the block we want to keep (the lower
1238 * numbered block) and path point to the block we want to drop.
1239 */
1240 memcpy(&state->altpath, &state->path, sizeof(state->path));
1241 if (blkno < blk->blkno) {
1242 error = xfs_da3_path_shift(state, &state->altpath, forward,
1243 0, &retval);
1244 } else {
1245 error = xfs_da3_path_shift(state, &state->path, forward,
1246 0, &retval);
1247 }
1248 if (error)
1249 return error;
1250 if (retval) {
1251 *action = 0;
1252 return 0;
1253 }
1254 *action = 1;
1255 return 0;
1256}
1257
1258/*
1259 * Pick up the last hashvalue from an intermediate node.
1260 */
1261STATIC uint
1262xfs_da3_node_lasthash(
1263 struct xfs_inode *dp,
1264 struct xfs_buf *bp,
1265 int *count)
1266{
1267 struct xfs_da_intnode *node;
1268 struct xfs_da_node_entry *btree;
1269 struct xfs_da3_icnode_hdr nodehdr;
1270
1271 node = bp->b_addr;
1272 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1273 if (count)
1274 *count = nodehdr.count;
1275 if (!nodehdr.count)
1276 return 0;
1277 btree = dp->d_ops->node_tree_p(node);
1278 return be32_to_cpu(btree[nodehdr.count - 1].hashval);
1279}
1280
1281/*
1282 * Walk back up the tree adjusting hash values as necessary,
1283 * when we stop making changes, return.
1284 */
1285void
1286xfs_da3_fixhashpath(
1287 struct xfs_da_state *state,
1288 struct xfs_da_state_path *path)
1289{
1290 struct xfs_da_state_blk *blk;
1291 struct xfs_da_intnode *node;
1292 struct xfs_da_node_entry *btree;
1293 xfs_dahash_t lasthash=0;
1294 int level;
1295 int count;
1296 struct xfs_inode *dp = state->args->dp;
1297
1298 trace_xfs_da_fixhashpath(state->args);
1299
1300 level = path->active-1;
1301 blk = &path->blk[ level ];
1302 switch (blk->magic) {
1303 case XFS_ATTR_LEAF_MAGIC:
1304 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1305 if (count == 0)
1306 return;
1307 break;
1308 case XFS_DIR2_LEAFN_MAGIC:
1309 lasthash = xfs_dir2_leaf_lasthash(dp, blk->bp, &count);
1310 if (count == 0)
1311 return;
1312 break;
1313 case XFS_DA_NODE_MAGIC:
1314 lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1315 if (count == 0)
1316 return;
1317 break;
1318 }
1319 for (blk--, level--; level >= 0; blk--, level--) {
1320 struct xfs_da3_icnode_hdr nodehdr;
1321
1322 node = blk->bp->b_addr;
1323 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1324 btree = dp->d_ops->node_tree_p(node);
1325 if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1326 break;
1327 blk->hashval = lasthash;
1328 btree[blk->index].hashval = cpu_to_be32(lasthash);
1329 xfs_trans_log_buf(state->args->trans, blk->bp,
1330 XFS_DA_LOGRANGE(node, &btree[blk->index],
1331 sizeof(*btree)));
1332
1333 lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1334 }
1335}
1336
1337/*
1338 * Remove an entry from an intermediate node.
1339 */
1340STATIC void
1341xfs_da3_node_remove(
1342 struct xfs_da_state *state,
1343 struct xfs_da_state_blk *drop_blk)
1344{
1345 struct xfs_da_intnode *node;
1346 struct xfs_da3_icnode_hdr nodehdr;
1347 struct xfs_da_node_entry *btree;
1348 int index;
1349 int tmp;
1350 struct xfs_inode *dp = state->args->dp;
1351
1352 trace_xfs_da_node_remove(state->args);
1353
1354 node = drop_blk->bp->b_addr;
1355 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1356 ASSERT(drop_blk->index < nodehdr.count);
1357 ASSERT(drop_blk->index >= 0);
1358
1359 /*
1360 * Copy over the offending entry, or just zero it out.
1361 */
1362 index = drop_blk->index;
1363 btree = dp->d_ops->node_tree_p(node);
1364 if (index < nodehdr.count - 1) {
1365 tmp = nodehdr.count - index - 1;
1366 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1367 memmove(&btree[index], &btree[index + 1], tmp);
1368 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1369 XFS_DA_LOGRANGE(node, &btree[index], tmp));
1370 index = nodehdr.count - 1;
1371 }
1372 memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1373 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1374 XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1375 nodehdr.count -= 1;
1376 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
1377 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1378 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
1379
1380 /*
1381 * Copy the last hash value from the block to propagate upwards.
1382 */
1383 drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1384}
1385
1386/*
1387 * Unbalance the elements between two intermediate nodes,
1388 * move all Btree elements from one node into another.
1389 */
1390STATIC void
1391xfs_da3_node_unbalance(
1392 struct xfs_da_state *state,
1393 struct xfs_da_state_blk *drop_blk,
1394 struct xfs_da_state_blk *save_blk)
1395{
1396 struct xfs_da_intnode *drop_node;
1397 struct xfs_da_intnode *save_node;
1398 struct xfs_da_node_entry *drop_btree;
1399 struct xfs_da_node_entry *save_btree;
1400 struct xfs_da3_icnode_hdr drop_hdr;
1401 struct xfs_da3_icnode_hdr save_hdr;
1402 struct xfs_trans *tp;
1403 int sindex;
1404 int tmp;
1405 struct xfs_inode *dp = state->args->dp;
1406
1407 trace_xfs_da_node_unbalance(state->args);
1408
1409 drop_node = drop_blk->bp->b_addr;
1410 save_node = save_blk->bp->b_addr;
1411 dp->d_ops->node_hdr_from_disk(&drop_hdr, drop_node);
1412 dp->d_ops->node_hdr_from_disk(&save_hdr, save_node);
1413 drop_btree = dp->d_ops->node_tree_p(drop_node);
1414 save_btree = dp->d_ops->node_tree_p(save_node);
1415 tp = state->args->trans;
1416
1417 /*
1418 * If the dying block has lower hashvals, then move all the
1419 * elements in the remaining block up to make a hole.
1420 */
1421 if ((be32_to_cpu(drop_btree[0].hashval) <
1422 be32_to_cpu(save_btree[0].hashval)) ||
1423 (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1424 be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1425 /* XXX: check this - is memmove dst correct? */
1426 tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1427 memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1428
1429 sindex = 0;
1430 xfs_trans_log_buf(tp, save_blk->bp,
1431 XFS_DA_LOGRANGE(save_node, &save_btree[0],
1432 (save_hdr.count + drop_hdr.count) *
1433 sizeof(xfs_da_node_entry_t)));
1434 } else {
1435 sindex = save_hdr.count;
1436 xfs_trans_log_buf(tp, save_blk->bp,
1437 XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1438 drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1439 }
1440
1441 /*
1442 * Move all the B-tree elements from drop_blk to save_blk.
1443 */
1444 tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1445 memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1446 save_hdr.count += drop_hdr.count;
1447
1448 dp->d_ops->node_hdr_to_disk(save_node, &save_hdr);
1449 xfs_trans_log_buf(tp, save_blk->bp,
1450 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1451 dp->d_ops->node_hdr_size));
1452
1453 /*
1454 * Save the last hashval in the remaining block for upward propagation.
1455 */
1456 save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1457}
1458
1459/*========================================================================
1460 * Routines used for finding things in the Btree.
1461 *========================================================================*/
1462
1463/*
1464 * Walk down the Btree looking for a particular filename, filling
1465 * in the state structure as we go.
1466 *
1467 * We will set the state structure to point to each of the elements
1468 * in each of the nodes where either the hashval is or should be.
1469 *
1470 * We support duplicate hashval's so for each entry in the current
1471 * node that could contain the desired hashval, descend. This is a
1472 * pruned depth-first tree search.
1473 */
1474int /* error */
1475xfs_da3_node_lookup_int(
1476 struct xfs_da_state *state,
1477 int *result)
1478{
1479 struct xfs_da_state_blk *blk;
1480 struct xfs_da_blkinfo *curr;
1481 struct xfs_da_intnode *node;
1482 struct xfs_da_node_entry *btree;
1483 struct xfs_da3_icnode_hdr nodehdr;
1484 struct xfs_da_args *args;
1485 xfs_dablk_t blkno;
1486 xfs_dahash_t hashval;
1487 xfs_dahash_t btreehashval;
1488 int probe;
1489 int span;
1490 int max;
1491 int error;
1492 int retval;
1493 unsigned int expected_level = 0;
1494 struct xfs_inode *dp = state->args->dp;
1495
1496 args = state->args;
1497
1498 /*
1499 * Descend thru the B-tree searching each level for the right
1500 * node to use, until the right hashval is found.
1501 */
1502 blkno = args->geo->leafblk;
1503 for (blk = &state->path.blk[0], state->path.active = 1;
1504 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1505 blk++, state->path.active++) {
1506 /*
1507 * Read the next node down in the tree.
1508 */
1509 blk->blkno = blkno;
1510 error = xfs_da3_node_read(args->trans, args->dp, blkno,
1511 -1, &blk->bp, args->whichfork);
1512 if (error) {
1513 blk->blkno = 0;
1514 state->path.active--;
1515 return error;
1516 }
1517 curr = blk->bp->b_addr;
1518 blk->magic = be16_to_cpu(curr->magic);
1519
1520 if (blk->magic == XFS_ATTR_LEAF_MAGIC ||
1521 blk->magic == XFS_ATTR3_LEAF_MAGIC) {
1522 blk->magic = XFS_ATTR_LEAF_MAGIC;
1523 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1524 break;
1525 }
1526
1527 if (blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1528 blk->magic == XFS_DIR3_LEAFN_MAGIC) {
1529 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1530 blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
1531 blk->bp, NULL);
1532 break;
1533 }
1534
1535 blk->magic = XFS_DA_NODE_MAGIC;
1536
1537
1538 /*
1539 * Search an intermediate node for a match.
1540 */
1541 node = blk->bp->b_addr;
1542 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1543 btree = dp->d_ops->node_tree_p(node);
1544
1545 /* Tree taller than we can handle; bail out! */
1546 if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
1547 return -EFSCORRUPTED;
1548
1549 /* Check the level from the root. */
1550 if (blkno == args->geo->leafblk)
1551 expected_level = nodehdr.level - 1;
1552 else if (expected_level != nodehdr.level)
1553 return -EFSCORRUPTED;
1554 else
1555 expected_level--;
1556
1557 max = nodehdr.count;
1558 blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1559
1560 /*
1561 * Binary search. (note: small blocks will skip loop)
1562 */
1563 probe = span = max / 2;
1564 hashval = args->hashval;
1565 while (span > 4) {
1566 span /= 2;
1567 btreehashval = be32_to_cpu(btree[probe].hashval);
1568 if (btreehashval < hashval)
1569 probe += span;
1570 else if (btreehashval > hashval)
1571 probe -= span;
1572 else
1573 break;
1574 }
1575 ASSERT((probe >= 0) && (probe < max));
1576 ASSERT((span <= 4) ||
1577 (be32_to_cpu(btree[probe].hashval) == hashval));
1578
1579 /*
1580 * Since we may have duplicate hashval's, find the first
1581 * matching hashval in the node.
1582 */
1583 while (probe > 0 &&
1584 be32_to_cpu(btree[probe].hashval) >= hashval) {
1585 probe--;
1586 }
1587 while (probe < max &&
1588 be32_to_cpu(btree[probe].hashval) < hashval) {
1589 probe++;
1590 }
1591
1592 /*
1593 * Pick the right block to descend on.
1594 */
1595 if (probe == max) {
1596 blk->index = max - 1;
1597 blkno = be32_to_cpu(btree[max - 1].before);
1598 } else {
1599 blk->index = probe;
1600 blkno = be32_to_cpu(btree[probe].before);
1601 }
1602
1603 /* We can't point back to the root. */
1604 if (blkno == args->geo->leafblk)
1605 return -EFSCORRUPTED;
1606 }
1607
1608 if (expected_level != 0)
1609 return -EFSCORRUPTED;
1610
1611 /*
1612 * A leaf block that ends in the hashval that we are interested in
1613 * (final hashval == search hashval) means that the next block may
1614 * contain more entries with the same hashval, shift upward to the
1615 * next leaf and keep searching.
1616 */
1617 for (;;) {
1618 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1619 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1620 &blk->index, state);
1621 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1622 retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1623 blk->index = args->index;
1624 args->blkno = blk->blkno;
1625 } else {
1626 ASSERT(0);
1627 return -EFSCORRUPTED;
1628 }
1629 if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1630 (blk->hashval == args->hashval)) {
1631 error = xfs_da3_path_shift(state, &state->path, 1, 1,
1632 &retval);
1633 if (error)
1634 return error;
1635 if (retval == 0) {
1636 continue;
1637 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1638 /* path_shift() gives ENOENT */
1639 retval = -ENOATTR;
1640 }
1641 }
1642 break;
1643 }
1644 *result = retval;
1645 return 0;
1646}
1647
1648/*========================================================================
1649 * Utility routines.
1650 *========================================================================*/
1651
1652/*
1653 * Compare two intermediate nodes for "order".
1654 */
1655STATIC int
1656xfs_da3_node_order(
1657 struct xfs_inode *dp,
1658 struct xfs_buf *node1_bp,
1659 struct xfs_buf *node2_bp)
1660{
1661 struct xfs_da_intnode *node1;
1662 struct xfs_da_intnode *node2;
1663 struct xfs_da_node_entry *btree1;
1664 struct xfs_da_node_entry *btree2;
1665 struct xfs_da3_icnode_hdr node1hdr;
1666 struct xfs_da3_icnode_hdr node2hdr;
1667
1668 node1 = node1_bp->b_addr;
1669 node2 = node2_bp->b_addr;
1670 dp->d_ops->node_hdr_from_disk(&node1hdr, node1);
1671 dp->d_ops->node_hdr_from_disk(&node2hdr, node2);
1672 btree1 = dp->d_ops->node_tree_p(node1);
1673 btree2 = dp->d_ops->node_tree_p(node2);
1674
1675 if (node1hdr.count > 0 && node2hdr.count > 0 &&
1676 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1677 (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1678 be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1679 return 1;
1680 }
1681 return 0;
1682}
1683
1684/*
1685 * Link a new block into a doubly linked list of blocks (of whatever type).
1686 */
1687int /* error */
1688xfs_da3_blk_link(
1689 struct xfs_da_state *state,
1690 struct xfs_da_state_blk *old_blk,
1691 struct xfs_da_state_blk *new_blk)
1692{
1693 struct xfs_da_blkinfo *old_info;
1694 struct xfs_da_blkinfo *new_info;
1695 struct xfs_da_blkinfo *tmp_info;
1696 struct xfs_da_args *args;
1697 struct xfs_buf *bp;
1698 int before = 0;
1699 int error;
1700 struct xfs_inode *dp = state->args->dp;
1701
1702 /*
1703 * Set up environment.
1704 */
1705 args = state->args;
1706 ASSERT(args != NULL);
1707 old_info = old_blk->bp->b_addr;
1708 new_info = new_blk->bp->b_addr;
1709 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1710 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1711 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1712
1713 switch (old_blk->magic) {
1714 case XFS_ATTR_LEAF_MAGIC:
1715 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1716 break;
1717 case XFS_DIR2_LEAFN_MAGIC:
1718 before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1719 break;
1720 case XFS_DA_NODE_MAGIC:
1721 before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1722 break;
1723 }
1724
1725 /*
1726 * Link blocks in appropriate order.
1727 */
1728 if (before) {
1729 /*
1730 * Link new block in before existing block.
1731 */
1732 trace_xfs_da_link_before(args);
1733 new_info->forw = cpu_to_be32(old_blk->blkno);
1734 new_info->back = old_info->back;
1735 if (old_info->back) {
1736 error = xfs_da3_node_read(args->trans, dp,
1737 be32_to_cpu(old_info->back),
1738 -1, &bp, args->whichfork);
1739 if (error)
1740 return error;
1741 ASSERT(bp != NULL);
1742 tmp_info = bp->b_addr;
1743 ASSERT(tmp_info->magic == old_info->magic);
1744 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1745 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1746 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1747 }
1748 old_info->back = cpu_to_be32(new_blk->blkno);
1749 } else {
1750 /*
1751 * Link new block in after existing block.
1752 */
1753 trace_xfs_da_link_after(args);
1754 new_info->forw = old_info->forw;
1755 new_info->back = cpu_to_be32(old_blk->blkno);
1756 if (old_info->forw) {
1757 error = xfs_da3_node_read(args->trans, dp,
1758 be32_to_cpu(old_info->forw),
1759 -1, &bp, args->whichfork);
1760 if (error)
1761 return error;
1762 ASSERT(bp != NULL);
1763 tmp_info = bp->b_addr;
1764 ASSERT(tmp_info->magic == old_info->magic);
1765 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1766 tmp_info->back = cpu_to_be32(new_blk->blkno);
1767 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1768 }
1769 old_info->forw = cpu_to_be32(new_blk->blkno);
1770 }
1771
1772 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1773 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1774 return 0;
1775}
1776
1777/*
1778 * Unlink a block from a doubly linked list of blocks.
1779 */
1780STATIC int /* error */
1781xfs_da3_blk_unlink(
1782 struct xfs_da_state *state,
1783 struct xfs_da_state_blk *drop_blk,
1784 struct xfs_da_state_blk *save_blk)
1785{
1786 struct xfs_da_blkinfo *drop_info;
1787 struct xfs_da_blkinfo *save_info;
1788 struct xfs_da_blkinfo *tmp_info;
1789 struct xfs_da_args *args;
1790 struct xfs_buf *bp;
1791 int error;
1792
1793 /*
1794 * Set up environment.
1795 */
1796 args = state->args;
1797 ASSERT(args != NULL);
1798 save_info = save_blk->bp->b_addr;
1799 drop_info = drop_blk->bp->b_addr;
1800 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1801 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1802 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1803 ASSERT(save_blk->magic == drop_blk->magic);
1804 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1805 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1806 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1807 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1808
1809 /*
1810 * Unlink the leaf block from the doubly linked chain of leaves.
1811 */
1812 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1813 trace_xfs_da_unlink_back(args);
1814 save_info->back = drop_info->back;
1815 if (drop_info->back) {
1816 error = xfs_da3_node_read(args->trans, args->dp,
1817 be32_to_cpu(drop_info->back),
1818 -1, &bp, args->whichfork);
1819 if (error)
1820 return error;
1821 ASSERT(bp != NULL);
1822 tmp_info = bp->b_addr;
1823 ASSERT(tmp_info->magic == save_info->magic);
1824 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1825 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1826 xfs_trans_log_buf(args->trans, bp, 0,
1827 sizeof(*tmp_info) - 1);
1828 }
1829 } else {
1830 trace_xfs_da_unlink_forward(args);
1831 save_info->forw = drop_info->forw;
1832 if (drop_info->forw) {
1833 error = xfs_da3_node_read(args->trans, args->dp,
1834 be32_to_cpu(drop_info->forw),
1835 -1, &bp, args->whichfork);
1836 if (error)
1837 return error;
1838 ASSERT(bp != NULL);
1839 tmp_info = bp->b_addr;
1840 ASSERT(tmp_info->magic == save_info->magic);
1841 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1842 tmp_info->back = cpu_to_be32(save_blk->blkno);
1843 xfs_trans_log_buf(args->trans, bp, 0,
1844 sizeof(*tmp_info) - 1);
1845 }
1846 }
1847
1848 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1849 return 0;
1850}
1851
1852/*
1853 * Move a path "forward" or "!forward" one block at the current level.
1854 *
1855 * This routine will adjust a "path" to point to the next block
1856 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1857 * Btree, including updating pointers to the intermediate nodes between
1858 * the new bottom and the root.
1859 */
1860int /* error */
1861xfs_da3_path_shift(
1862 struct xfs_da_state *state,
1863 struct xfs_da_state_path *path,
1864 int forward,
1865 int release,
1866 int *result)
1867{
1868 struct xfs_da_state_blk *blk;
1869 struct xfs_da_blkinfo *info;
1870 struct xfs_da_intnode *node;
1871 struct xfs_da_args *args;
1872 struct xfs_da_node_entry *btree;
1873 struct xfs_da3_icnode_hdr nodehdr;
1874 struct xfs_buf *bp;
1875 xfs_dablk_t blkno = 0;
1876 int level;
1877 int error;
1878 struct xfs_inode *dp = state->args->dp;
1879
1880 trace_xfs_da_path_shift(state->args);
1881
1882 /*
1883 * Roll up the Btree looking for the first block where our
1884 * current index is not at the edge of the block. Note that
1885 * we skip the bottom layer because we want the sibling block.
1886 */
1887 args = state->args;
1888 ASSERT(args != NULL);
1889 ASSERT(path != NULL);
1890 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1891 level = (path->active-1) - 1; /* skip bottom layer in path */
1892 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1893 node = blk->bp->b_addr;
1894 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1895 btree = dp->d_ops->node_tree_p(node);
1896
1897 if (forward && (blk->index < nodehdr.count - 1)) {
1898 blk->index++;
1899 blkno = be32_to_cpu(btree[blk->index].before);
1900 break;
1901 } else if (!forward && (blk->index > 0)) {
1902 blk->index--;
1903 blkno = be32_to_cpu(btree[blk->index].before);
1904 break;
1905 }
1906 }
1907 if (level < 0) {
1908 *result = -ENOENT; /* we're out of our tree */
1909 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1910 return 0;
1911 }
1912
1913 /*
1914 * Roll down the edge of the subtree until we reach the
1915 * same depth we were at originally.
1916 */
1917 for (blk++, level++; level < path->active; blk++, level++) {
1918 /*
1919 * Read the next child block into a local buffer.
1920 */
1921 error = xfs_da3_node_read(args->trans, dp, blkno, -1, &bp,
1922 args->whichfork);
1923 if (error)
1924 return error;
1925
1926 /*
1927 * Release the old block (if it's dirty, the trans doesn't
1928 * actually let go) and swap the local buffer into the path
1929 * structure. This ensures failure of the above read doesn't set
1930 * a NULL buffer in an active slot in the path.
1931 */
1932 if (release)
1933 xfs_trans_brelse(args->trans, blk->bp);
1934 blk->blkno = blkno;
1935 blk->bp = bp;
1936
1937 info = blk->bp->b_addr;
1938 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1939 info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
1940 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1941 info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1942 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1943 info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1944
1945
1946 /*
1947 * Note: we flatten the magic number to a single type so we
1948 * don't have to compare against crc/non-crc types elsewhere.
1949 */
1950 switch (be16_to_cpu(info->magic)) {
1951 case XFS_DA_NODE_MAGIC:
1952 case XFS_DA3_NODE_MAGIC:
1953 blk->magic = XFS_DA_NODE_MAGIC;
1954 node = (xfs_da_intnode_t *)info;
1955 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1956 btree = dp->d_ops->node_tree_p(node);
1957 blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1958 if (forward)
1959 blk->index = 0;
1960 else
1961 blk->index = nodehdr.count - 1;
1962 blkno = be32_to_cpu(btree[blk->index].before);
1963 break;
1964 case XFS_ATTR_LEAF_MAGIC:
1965 case XFS_ATTR3_LEAF_MAGIC:
1966 blk->magic = XFS_ATTR_LEAF_MAGIC;
1967 ASSERT(level == path->active-1);
1968 blk->index = 0;
1969 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1970 break;
1971 case XFS_DIR2_LEAFN_MAGIC:
1972 case XFS_DIR3_LEAFN_MAGIC:
1973 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1974 ASSERT(level == path->active-1);
1975 blk->index = 0;
1976 blk->hashval = xfs_dir2_leaf_lasthash(args->dp,
1977 blk->bp, NULL);
1978 break;
1979 default:
1980 ASSERT(0);
1981 break;
1982 }
1983 }
1984 *result = 0;
1985 return 0;
1986}
1987
1988
1989/*========================================================================
1990 * Utility routines.
1991 *========================================================================*/
1992
1993/*
1994 * Implement a simple hash on a character string.
1995 * Rotate the hash value by 7 bits, then XOR each character in.
1996 * This is implemented with some source-level loop unrolling.
1997 */
1998xfs_dahash_t
1999xfs_da_hashname(const uint8_t *name, int namelen)
2000{
2001 xfs_dahash_t hash;
2002
2003 /*
2004 * Do four characters at a time as long as we can.
2005 */
2006 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
2007 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
2008 (name[3] << 0) ^ rol32(hash, 7 * 4);
2009
2010 /*
2011 * Now do the rest of the characters.
2012 */
2013 switch (namelen) {
2014 case 3:
2015 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
2016 rol32(hash, 7 * 3);
2017 case 2:
2018 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
2019 case 1:
2020 return (name[0] << 0) ^ rol32(hash, 7 * 1);
2021 default: /* case 0: */
2022 return hash;
2023 }
2024}
2025
2026enum xfs_dacmp
2027xfs_da_compname(
2028 struct xfs_da_args *args,
2029 const unsigned char *name,
2030 int len)
2031{
2032 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
2033 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
2034}
2035
2036static xfs_dahash_t
2037xfs_default_hashname(
2038 struct xfs_name *name)
2039{
2040 return xfs_da_hashname(name->name, name->len);
2041}
2042
2043const struct xfs_nameops xfs_default_nameops = {
2044 .hashname = xfs_default_hashname,
2045 .compname = xfs_da_compname
2046};
2047
2048int
2049xfs_da_grow_inode_int(
2050 struct xfs_da_args *args,
2051 xfs_fileoff_t *bno,
2052 int count)
2053{
2054 struct xfs_trans *tp = args->trans;
2055 struct xfs_inode *dp = args->dp;
2056 int w = args->whichfork;
2057 xfs_rfsblock_t nblks = dp->i_d.di_nblocks;
2058 struct xfs_bmbt_irec map, *mapp;
2059 int nmap, error, got, i, mapi;
2060
2061 /*
2062 * Find a spot in the file space to put the new block.
2063 */
2064 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2065 if (error)
2066 return error;
2067
2068 /*
2069 * Try mapping it in one filesystem block.
2070 */
2071 nmap = 1;
2072 ASSERT(args->firstblock != NULL);
2073 error = xfs_bmapi_write(tp, dp, *bno, count,
2074 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2075 args->firstblock, args->total, &map, &nmap,
2076 args->dfops);
2077 if (error)
2078 return error;
2079
2080 ASSERT(nmap <= 1);
2081 if (nmap == 1) {
2082 mapp = ↦
2083 mapi = 1;
2084 } else if (nmap == 0 && count > 1) {
2085 xfs_fileoff_t b;
2086 int c;
2087
2088 /*
2089 * If we didn't get it and the block might work if fragmented,
2090 * try without the CONTIG flag. Loop until we get it all.
2091 */
2092 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
2093 for (b = *bno, mapi = 0; b < *bno + count; ) {
2094 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
2095 c = (int)(*bno + count - b);
2096 error = xfs_bmapi_write(tp, dp, b, c,
2097 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2098 args->firstblock, args->total,
2099 &mapp[mapi], &nmap, args->dfops);
2100 if (error)
2101 goto out_free_map;
2102 if (nmap < 1)
2103 break;
2104 mapi += nmap;
2105 b = mapp[mapi - 1].br_startoff +
2106 mapp[mapi - 1].br_blockcount;
2107 }
2108 } else {
2109 mapi = 0;
2110 mapp = NULL;
2111 }
2112
2113 /*
2114 * Count the blocks we got, make sure it matches the total.
2115 */
2116 for (i = 0, got = 0; i < mapi; i++)
2117 got += mapp[i].br_blockcount;
2118 if (got != count || mapp[0].br_startoff != *bno ||
2119 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2120 *bno + count) {
2121 error = -ENOSPC;
2122 goto out_free_map;
2123 }
2124
2125 /* account for newly allocated blocks in reserved blocks total */
2126 args->total -= dp->i_d.di_nblocks - nblks;
2127
2128out_free_map:
2129 if (mapp != &map)
2130 kmem_free(mapp);
2131 return error;
2132}
2133
2134/*
2135 * Add a block to the btree ahead of the file.
2136 * Return the new block number to the caller.
2137 */
2138int
2139xfs_da_grow_inode(
2140 struct xfs_da_args *args,
2141 xfs_dablk_t *new_blkno)
2142{
2143 xfs_fileoff_t bno;
2144 int error;
2145
2146 trace_xfs_da_grow_inode(args);
2147
2148 bno = args->geo->leafblk;
2149 error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2150 if (!error)
2151 *new_blkno = (xfs_dablk_t)bno;
2152 return error;
2153}
2154
2155/*
2156 * Ick. We need to always be able to remove a btree block, even
2157 * if there's no space reservation because the filesystem is full.
2158 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2159 * It swaps the target block with the last block in the file. The
2160 * last block in the file can always be removed since it can't cause
2161 * a bmap btree split to do that.
2162 */
2163STATIC int
2164xfs_da3_swap_lastblock(
2165 struct xfs_da_args *args,
2166 xfs_dablk_t *dead_blknop,
2167 struct xfs_buf **dead_bufp)
2168{
2169 struct xfs_da_blkinfo *dead_info;
2170 struct xfs_da_blkinfo *sib_info;
2171 struct xfs_da_intnode *par_node;
2172 struct xfs_da_intnode *dead_node;
2173 struct xfs_dir2_leaf *dead_leaf2;
2174 struct xfs_da_node_entry *btree;
2175 struct xfs_da3_icnode_hdr par_hdr;
2176 struct xfs_inode *dp;
2177 struct xfs_trans *tp;
2178 struct xfs_mount *mp;
2179 struct xfs_buf *dead_buf;
2180 struct xfs_buf *last_buf;
2181 struct xfs_buf *sib_buf;
2182 struct xfs_buf *par_buf;
2183 xfs_dahash_t dead_hash;
2184 xfs_fileoff_t lastoff;
2185 xfs_dablk_t dead_blkno;
2186 xfs_dablk_t last_blkno;
2187 xfs_dablk_t sib_blkno;
2188 xfs_dablk_t par_blkno;
2189 int error;
2190 int w;
2191 int entno;
2192 int level;
2193 int dead_level;
2194
2195 trace_xfs_da_swap_lastblock(args);
2196
2197 dead_buf = *dead_bufp;
2198 dead_blkno = *dead_blknop;
2199 tp = args->trans;
2200 dp = args->dp;
2201 w = args->whichfork;
2202 ASSERT(w == XFS_DATA_FORK);
2203 mp = dp->i_mount;
2204 lastoff = args->geo->freeblk;
2205 error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2206 if (error)
2207 return error;
2208 if (unlikely(lastoff == 0)) {
2209 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
2210 mp);
2211 return -EFSCORRUPTED;
2212 }
2213 /*
2214 * Read the last block in the btree space.
2215 */
2216 last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2217 error = xfs_da3_node_read(tp, dp, last_blkno, -1, &last_buf, w);
2218 if (error)
2219 return error;
2220 /*
2221 * Copy the last block into the dead buffer and log it.
2222 */
2223 memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2224 xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2225 dead_info = dead_buf->b_addr;
2226 /*
2227 * Get values from the moved block.
2228 */
2229 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2230 dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2231 struct xfs_dir3_icleaf_hdr leafhdr;
2232 struct xfs_dir2_leaf_entry *ents;
2233
2234 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2235 dp->d_ops->leaf_hdr_from_disk(&leafhdr, dead_leaf2);
2236 ents = dp->d_ops->leaf_ents_p(dead_leaf2);
2237 dead_level = 0;
2238 dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2239 } else {
2240 struct xfs_da3_icnode_hdr deadhdr;
2241
2242 dead_node = (xfs_da_intnode_t *)dead_info;
2243 dp->d_ops->node_hdr_from_disk(&deadhdr, dead_node);
2244 btree = dp->d_ops->node_tree_p(dead_node);
2245 dead_level = deadhdr.level;
2246 dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2247 }
2248 sib_buf = par_buf = NULL;
2249 /*
2250 * If the moved block has a left sibling, fix up the pointers.
2251 */
2252 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2253 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2254 if (error)
2255 goto done;
2256 sib_info = sib_buf->b_addr;
2257 if (unlikely(
2258 be32_to_cpu(sib_info->forw) != last_blkno ||
2259 sib_info->magic != dead_info->magic)) {
2260 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
2261 XFS_ERRLEVEL_LOW, mp);
2262 error = -EFSCORRUPTED;
2263 goto done;
2264 }
2265 sib_info->forw = cpu_to_be32(dead_blkno);
2266 xfs_trans_log_buf(tp, sib_buf,
2267 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2268 sizeof(sib_info->forw)));
2269 sib_buf = NULL;
2270 }
2271 /*
2272 * If the moved block has a right sibling, fix up the pointers.
2273 */
2274 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2275 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2276 if (error)
2277 goto done;
2278 sib_info = sib_buf->b_addr;
2279 if (unlikely(
2280 be32_to_cpu(sib_info->back) != last_blkno ||
2281 sib_info->magic != dead_info->magic)) {
2282 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
2283 XFS_ERRLEVEL_LOW, mp);
2284 error = -EFSCORRUPTED;
2285 goto done;
2286 }
2287 sib_info->back = cpu_to_be32(dead_blkno);
2288 xfs_trans_log_buf(tp, sib_buf,
2289 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2290 sizeof(sib_info->back)));
2291 sib_buf = NULL;
2292 }
2293 par_blkno = args->geo->leafblk;
2294 level = -1;
2295 /*
2296 * Walk down the tree looking for the parent of the moved block.
2297 */
2298 for (;;) {
2299 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2300 if (error)
2301 goto done;
2302 par_node = par_buf->b_addr;
2303 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2304 if (level >= 0 && level != par_hdr.level + 1) {
2305 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
2306 XFS_ERRLEVEL_LOW, mp);
2307 error = -EFSCORRUPTED;
2308 goto done;
2309 }
2310 level = par_hdr.level;
2311 btree = dp->d_ops->node_tree_p(par_node);
2312 for (entno = 0;
2313 entno < par_hdr.count &&
2314 be32_to_cpu(btree[entno].hashval) < dead_hash;
2315 entno++)
2316 continue;
2317 if (entno == par_hdr.count) {
2318 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
2319 XFS_ERRLEVEL_LOW, mp);
2320 error = -EFSCORRUPTED;
2321 goto done;
2322 }
2323 par_blkno = be32_to_cpu(btree[entno].before);
2324 if (level == dead_level + 1)
2325 break;
2326 xfs_trans_brelse(tp, par_buf);
2327 par_buf = NULL;
2328 }
2329 /*
2330 * We're in the right parent block.
2331 * Look for the right entry.
2332 */
2333 for (;;) {
2334 for (;
2335 entno < par_hdr.count &&
2336 be32_to_cpu(btree[entno].before) != last_blkno;
2337 entno++)
2338 continue;
2339 if (entno < par_hdr.count)
2340 break;
2341 par_blkno = par_hdr.forw;
2342 xfs_trans_brelse(tp, par_buf);
2343 par_buf = NULL;
2344 if (unlikely(par_blkno == 0)) {
2345 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
2346 XFS_ERRLEVEL_LOW, mp);
2347 error = -EFSCORRUPTED;
2348 goto done;
2349 }
2350 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2351 if (error)
2352 goto done;
2353 par_node = par_buf->b_addr;
2354 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2355 if (par_hdr.level != level) {
2356 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
2357 XFS_ERRLEVEL_LOW, mp);
2358 error = -EFSCORRUPTED;
2359 goto done;
2360 }
2361 btree = dp->d_ops->node_tree_p(par_node);
2362 entno = 0;
2363 }
2364 /*
2365 * Update the parent entry pointing to the moved block.
2366 */
2367 btree[entno].before = cpu_to_be32(dead_blkno);
2368 xfs_trans_log_buf(tp, par_buf,
2369 XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2370 sizeof(btree[entno].before)));
2371 *dead_blknop = last_blkno;
2372 *dead_bufp = last_buf;
2373 return 0;
2374done:
2375 if (par_buf)
2376 xfs_trans_brelse(tp, par_buf);
2377 if (sib_buf)
2378 xfs_trans_brelse(tp, sib_buf);
2379 xfs_trans_brelse(tp, last_buf);
2380 return error;
2381}
2382
2383/*
2384 * Remove a btree block from a directory or attribute.
2385 */
2386int
2387xfs_da_shrink_inode(
2388 xfs_da_args_t *args,
2389 xfs_dablk_t dead_blkno,
2390 struct xfs_buf *dead_buf)
2391{
2392 xfs_inode_t *dp;
2393 int done, error, w, count;
2394 xfs_trans_t *tp;
2395
2396 trace_xfs_da_shrink_inode(args);
2397
2398 dp = args->dp;
2399 w = args->whichfork;
2400 tp = args->trans;
2401 count = args->geo->fsbcount;
2402 for (;;) {
2403 /*
2404 * Remove extents. If we get ENOSPC for a dir we have to move
2405 * the last block to the place we want to kill.
2406 */
2407 error = xfs_bunmapi(tp, dp, dead_blkno, count,
2408 xfs_bmapi_aflag(w), 0, args->firstblock,
2409 args->dfops, &done);
2410 if (error == -ENOSPC) {
2411 if (w != XFS_DATA_FORK)
2412 break;
2413 error = xfs_da3_swap_lastblock(args, &dead_blkno,
2414 &dead_buf);
2415 if (error)
2416 break;
2417 } else {
2418 break;
2419 }
2420 }
2421 xfs_trans_binval(tp, dead_buf);
2422 return error;
2423}
2424
2425/*
2426 * See if the mapping(s) for this btree block are valid, i.e.
2427 * don't contain holes, are logically contiguous, and cover the whole range.
2428 */
2429STATIC int
2430xfs_da_map_covers_blocks(
2431 int nmap,
2432 xfs_bmbt_irec_t *mapp,
2433 xfs_dablk_t bno,
2434 int count)
2435{
2436 int i;
2437 xfs_fileoff_t off;
2438
2439 for (i = 0, off = bno; i < nmap; i++) {
2440 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2441 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2442 return 0;
2443 }
2444 if (off != mapp[i].br_startoff) {
2445 return 0;
2446 }
2447 off += mapp[i].br_blockcount;
2448 }
2449 return off == bno + count;
2450}
2451
2452/*
2453 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
2454 *
2455 * For the single map case, it is assumed that the caller has provided a pointer
2456 * to a valid xfs_buf_map. For the multiple map case, this function will
2457 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
2458 * map pointer with the allocated map.
2459 */
2460static int
2461xfs_buf_map_from_irec(
2462 struct xfs_mount *mp,
2463 struct xfs_buf_map **mapp,
2464 int *nmaps,
2465 struct xfs_bmbt_irec *irecs,
2466 int nirecs)
2467{
2468 struct xfs_buf_map *map;
2469 int i;
2470
2471 ASSERT(*nmaps == 1);
2472 ASSERT(nirecs >= 1);
2473
2474 if (nirecs > 1) {
2475 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map),
2476 KM_SLEEP | KM_NOFS);
2477 if (!map)
2478 return -ENOMEM;
2479 *mapp = map;
2480 }
2481
2482 *nmaps = nirecs;
2483 map = *mapp;
2484 for (i = 0; i < *nmaps; i++) {
2485 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
2486 irecs[i].br_startblock != HOLESTARTBLOCK);
2487 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2488 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2489 }
2490 return 0;
2491}
2492
2493/*
2494 * Map the block we are given ready for reading. There are three possible return
2495 * values:
2496 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
2497 * caller knows not to execute a subsequent read.
2498 * 0 - if we mapped the block successfully
2499 * >0 - positive error number if there was an error.
2500 */
2501static int
2502xfs_dabuf_map(
2503 struct xfs_inode *dp,
2504 xfs_dablk_t bno,
2505 xfs_daddr_t mappedbno,
2506 int whichfork,
2507 struct xfs_buf_map **map,
2508 int *nmaps)
2509{
2510 struct xfs_mount *mp = dp->i_mount;
2511 int nfsb;
2512 int error = 0;
2513 struct xfs_bmbt_irec irec;
2514 struct xfs_bmbt_irec *irecs = &irec;
2515 int nirecs;
2516
2517 ASSERT(map && *map);
2518 ASSERT(*nmaps == 1);
2519
2520 if (whichfork == XFS_DATA_FORK)
2521 nfsb = mp->m_dir_geo->fsbcount;
2522 else
2523 nfsb = mp->m_attr_geo->fsbcount;
2524
2525 /*
2526 * Caller doesn't have a mapping. -2 means don't complain
2527 * if we land in a hole.
2528 */
2529 if (mappedbno == -1 || mappedbno == -2) {
2530 /*
2531 * Optimize the one-block case.
2532 */
2533 if (nfsb != 1)
2534 irecs = kmem_zalloc(sizeof(irec) * nfsb,
2535 KM_SLEEP | KM_NOFS);
2536
2537 nirecs = nfsb;
2538 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2539 &nirecs, xfs_bmapi_aflag(whichfork));
2540 if (error)
2541 goto out;
2542 } else {
2543 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2544 irecs->br_startoff = (xfs_fileoff_t)bno;
2545 irecs->br_blockcount = nfsb;
2546 irecs->br_state = 0;
2547 nirecs = 1;
2548 }
2549
2550 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2551 error = mappedbno == -2 ? -1 : -EFSCORRUPTED;
2552 if (unlikely(error == -EFSCORRUPTED)) {
2553 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2554 int i;
2555 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2556 __func__, (long long)bno,
2557 (long long)dp->i_ino);
2558 for (i = 0; i < *nmaps; i++) {
2559 xfs_alert(mp,
2560"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2561 i,
2562 (long long)irecs[i].br_startoff,
2563 (long long)irecs[i].br_startblock,
2564 (long long)irecs[i].br_blockcount,
2565 irecs[i].br_state);
2566 }
2567 }
2568 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2569 XFS_ERRLEVEL_LOW, mp);
2570 }
2571 goto out;
2572 }
2573 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2574out:
2575 if (irecs != &irec)
2576 kmem_free(irecs);
2577 return error;
2578}
2579
2580/*
2581 * Get a buffer for the dir/attr block.
2582 */
2583int
2584xfs_da_get_buf(
2585 struct xfs_trans *trans,
2586 struct xfs_inode *dp,
2587 xfs_dablk_t bno,
2588 xfs_daddr_t mappedbno,
2589 struct xfs_buf **bpp,
2590 int whichfork)
2591{
2592 struct xfs_buf *bp;
2593 struct xfs_buf_map map;
2594 struct xfs_buf_map *mapp;
2595 int nmap;
2596 int error;
2597
2598 *bpp = NULL;
2599 mapp = ↦
2600 nmap = 1;
2601 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2602 &mapp, &nmap);
2603 if (error) {
2604 /* mapping a hole is not an error, but we don't continue */
2605 if (error == -1)
2606 error = 0;
2607 goto out_free;
2608 }
2609
2610 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2611 mapp, nmap, 0);
2612 error = bp ? bp->b_error : -EIO;
2613 if (error) {
2614 if (bp)
2615 xfs_trans_brelse(trans, bp);
2616 goto out_free;
2617 }
2618
2619 *bpp = bp;
2620
2621out_free:
2622 if (mapp != &map)
2623 kmem_free(mapp);
2624
2625 return error;
2626}
2627
2628/*
2629 * Get a buffer for the dir/attr block, fill in the contents.
2630 */
2631int
2632xfs_da_read_buf(
2633 struct xfs_trans *trans,
2634 struct xfs_inode *dp,
2635 xfs_dablk_t bno,
2636 xfs_daddr_t mappedbno,
2637 struct xfs_buf **bpp,
2638 int whichfork,
2639 const struct xfs_buf_ops *ops)
2640{
2641 struct xfs_buf *bp;
2642 struct xfs_buf_map map;
2643 struct xfs_buf_map *mapp;
2644 int nmap;
2645 int error;
2646
2647 *bpp = NULL;
2648 mapp = ↦
2649 nmap = 1;
2650 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2651 &mapp, &nmap);
2652 if (error) {
2653 /* mapping a hole is not an error, but we don't continue */
2654 if (error == -1)
2655 error = 0;
2656 goto out_free;
2657 }
2658
2659 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2660 dp->i_mount->m_ddev_targp,
2661 mapp, nmap, 0, &bp, ops);
2662 if (error)
2663 goto out_free;
2664
2665 if (whichfork == XFS_ATTR_FORK)
2666 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2667 else
2668 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2669 *bpp = bp;
2670out_free:
2671 if (mapp != &map)
2672 kmem_free(mapp);
2673
2674 return error;
2675}
2676
2677/*
2678 * Readahead the dir/attr block.
2679 */
2680int
2681xfs_da_reada_buf(
2682 struct xfs_inode *dp,
2683 xfs_dablk_t bno,
2684 xfs_daddr_t mappedbno,
2685 int whichfork,
2686 const struct xfs_buf_ops *ops)
2687{
2688 struct xfs_buf_map map;
2689 struct xfs_buf_map *mapp;
2690 int nmap;
2691 int error;
2692
2693 mapp = ↦
2694 nmap = 1;
2695 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2696 &mapp, &nmap);
2697 if (error) {
2698 /* mapping a hole is not an error, but we don't continue */
2699 if (error == -1)
2700 error = 0;
2701 goto out_free;
2702 }
2703
2704 mappedbno = mapp[0].bm_bn;
2705 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2706
2707out_free:
2708 if (mapp != &map)
2709 kmem_free(mapp);
2710
2711 return error;
2712}
1/*
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 struct xfs_buf *bp;
360 int max;
361 int action = 0;
362 int error;
363 int i;
364
365 trace_xfs_da_split(state->args);
366
367 /*
368 * Walk back up the tree splitting/inserting/adjusting as necessary.
369 * If we need to insert and there isn't room, split the node, then
370 * decide which fragment to insert the new block from below into.
371 * Note that we may split the root this way, but we need more fixup.
372 */
373 max = state->path.active - 1;
374 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
375 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
376 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
377
378 addblk = &state->path.blk[max]; /* initial dummy value */
379 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
380 oldblk = &state->path.blk[i];
381 newblk = &state->altpath.blk[i];
382
383 /*
384 * If a leaf node then
385 * Allocate a new leaf node, then rebalance across them.
386 * else if an intermediate node then
387 * We split on the last layer, must we split the node?
388 */
389 switch (oldblk->magic) {
390 case XFS_ATTR_LEAF_MAGIC:
391 error = xfs_attr3_leaf_split(state, oldblk, newblk);
392 if ((error != 0) && (error != -ENOSPC)) {
393 return error; /* GROT: attr is inconsistent */
394 }
395 if (!error) {
396 addblk = newblk;
397 break;
398 }
399 /*
400 * Entry wouldn't fit, split the leaf again.
401 */
402 state->extravalid = 1;
403 if (state->inleaf) {
404 state->extraafter = 0; /* before newblk */
405 trace_xfs_attr_leaf_split_before(state->args);
406 error = xfs_attr3_leaf_split(state, oldblk,
407 &state->extrablk);
408 } else {
409 state->extraafter = 1; /* after newblk */
410 trace_xfs_attr_leaf_split_after(state->args);
411 error = xfs_attr3_leaf_split(state, newblk,
412 &state->extrablk);
413 }
414 if (error)
415 return error; /* GROT: attr inconsistent */
416 addblk = newblk;
417 break;
418 case XFS_DIR2_LEAFN_MAGIC:
419 error = xfs_dir2_leafn_split(state, oldblk, newblk);
420 if (error)
421 return error;
422 addblk = newblk;
423 break;
424 case XFS_DA_NODE_MAGIC:
425 error = xfs_da3_node_split(state, oldblk, newblk, addblk,
426 max - i, &action);
427 addblk->bp = NULL;
428 if (error)
429 return error; /* GROT: dir is inconsistent */
430 /*
431 * Record the newly split block for the next time thru?
432 */
433 if (action)
434 addblk = newblk;
435 else
436 addblk = NULL;
437 break;
438 }
439
440 /*
441 * Update the btree to show the new hashval for this child.
442 */
443 xfs_da3_fixhashpath(state, &state->path);
444 }
445 if (!addblk)
446 return 0;
447
448 /*
449 * Split the root node.
450 */
451 ASSERT(state->path.active == 0);
452 oldblk = &state->path.blk[0];
453 error = xfs_da3_root_split(state, oldblk, addblk);
454 if (error) {
455 addblk->bp = NULL;
456 return error; /* GROT: dir is inconsistent */
457 }
458
459 /*
460 * Update pointers to the node which used to be block 0 and
461 * just got bumped because of the addition of a new root node.
462 * There might be three blocks involved if a double split occurred,
463 * and the original block 0 could be at any position in the list.
464 *
465 * Note: the magic numbers and sibling pointers are in the same
466 * physical place for both v2 and v3 headers (by design). Hence it
467 * doesn't matter which version of the xfs_da_intnode structure we use
468 * here as the result will be the same using either structure.
469 */
470 node = oldblk->bp->b_addr;
471 if (node->hdr.info.forw) {
472 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
473 bp = addblk->bp;
474 } else {
475 ASSERT(state->extravalid);
476 bp = state->extrablk.bp;
477 }
478 node = bp->b_addr;
479 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
480 xfs_trans_log_buf(state->args->trans, bp,
481 XFS_DA_LOGRANGE(node, &node->hdr.info,
482 sizeof(node->hdr.info)));
483 }
484 node = oldblk->bp->b_addr;
485 if (node->hdr.info.back) {
486 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
487 bp = addblk->bp;
488 } else {
489 ASSERT(state->extravalid);
490 bp = state->extrablk.bp;
491 }
492 node = bp->b_addr;
493 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
494 xfs_trans_log_buf(state->args->trans, bp,
495 XFS_DA_LOGRANGE(node, &node->hdr.info,
496 sizeof(node->hdr.info)));
497 }
498 addblk->bp = NULL;
499 return 0;
500}
501
502/*
503 * Split the root. We have to create a new root and point to the two
504 * parts (the split old root) that we just created. Copy block zero to
505 * the EOF, extending the inode in process.
506 */
507STATIC int /* error */
508xfs_da3_root_split(
509 struct xfs_da_state *state,
510 struct xfs_da_state_blk *blk1,
511 struct xfs_da_state_blk *blk2)
512{
513 struct xfs_da_intnode *node;
514 struct xfs_da_intnode *oldroot;
515 struct xfs_da_node_entry *btree;
516 struct xfs_da3_icnode_hdr nodehdr;
517 struct xfs_da_args *args;
518 struct xfs_buf *bp;
519 struct xfs_inode *dp;
520 struct xfs_trans *tp;
521 struct xfs_dir2_leaf *leaf;
522 xfs_dablk_t blkno;
523 int level;
524 int error;
525 int size;
526
527 trace_xfs_da_root_split(state->args);
528
529 /*
530 * Copy the existing (incorrect) block from the root node position
531 * to a free space somewhere.
532 */
533 args = state->args;
534 error = xfs_da_grow_inode(args, &blkno);
535 if (error)
536 return error;
537
538 dp = args->dp;
539 tp = args->trans;
540 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
541 if (error)
542 return error;
543 node = bp->b_addr;
544 oldroot = blk1->bp->b_addr;
545 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
546 oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC)) {
547 struct xfs_da3_icnode_hdr icnodehdr;
548
549 dp->d_ops->node_hdr_from_disk(&icnodehdr, oldroot);
550 btree = dp->d_ops->node_tree_p(oldroot);
551 size = (int)((char *)&btree[icnodehdr.count] - (char *)oldroot);
552 level = icnodehdr.level;
553
554 /*
555 * we are about to copy oldroot to bp, so set up the type
556 * of bp while we know exactly what it will be.
557 */
558 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DA_NODE_BUF);
559 } else {
560 struct xfs_dir3_icleaf_hdr leafhdr;
561 struct xfs_dir2_leaf_entry *ents;
562
563 leaf = (xfs_dir2_leaf_t *)oldroot;
564 dp->d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
565 ents = dp->d_ops->leaf_ents_p(leaf);
566
567 ASSERT(leafhdr.magic == XFS_DIR2_LEAFN_MAGIC ||
568 leafhdr.magic == XFS_DIR3_LEAFN_MAGIC);
569 size = (int)((char *)&ents[leafhdr.count] - (char *)leaf);
570 level = 0;
571
572 /*
573 * we are about to copy oldroot to bp, so set up the type
574 * of bp while we know exactly what it will be.
575 */
576 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DIR_LEAFN_BUF);
577 }
578
579 /*
580 * we can copy most of the information in the node from one block to
581 * another, but for CRC enabled headers we have to make sure that the
582 * block specific identifiers are kept intact. We update the buffer
583 * directly for this.
584 */
585 memcpy(node, oldroot, size);
586 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
587 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
588 struct xfs_da3_intnode *node3 = (struct xfs_da3_intnode *)node;
589
590 node3->hdr.info.blkno = cpu_to_be64(bp->b_bn);
591 }
592 xfs_trans_log_buf(tp, bp, 0, size - 1);
593
594 bp->b_ops = blk1->bp->b_ops;
595 xfs_trans_buf_copy_type(bp, blk1->bp);
596 blk1->bp = bp;
597 blk1->blkno = blkno;
598
599 /*
600 * Set up the new root node.
601 */
602 error = xfs_da3_node_create(args,
603 (args->whichfork == XFS_DATA_FORK) ? args->geo->leafblk : 0,
604 level + 1, &bp, args->whichfork);
605 if (error)
606 return error;
607
608 node = bp->b_addr;
609 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
610 btree = dp->d_ops->node_tree_p(node);
611 btree[0].hashval = cpu_to_be32(blk1->hashval);
612 btree[0].before = cpu_to_be32(blk1->blkno);
613 btree[1].hashval = cpu_to_be32(blk2->hashval);
614 btree[1].before = cpu_to_be32(blk2->blkno);
615 nodehdr.count = 2;
616 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
617
618#ifdef DEBUG
619 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
620 oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
621 ASSERT(blk1->blkno >= args->geo->leafblk &&
622 blk1->blkno < args->geo->freeblk);
623 ASSERT(blk2->blkno >= args->geo->leafblk &&
624 blk2->blkno < args->geo->freeblk);
625 }
626#endif
627
628 /* Header is already logged by xfs_da_node_create */
629 xfs_trans_log_buf(tp, bp,
630 XFS_DA_LOGRANGE(node, btree, sizeof(xfs_da_node_entry_t) * 2));
631
632 return 0;
633}
634
635/*
636 * Split the node, rebalance, then add the new entry.
637 */
638STATIC int /* error */
639xfs_da3_node_split(
640 struct xfs_da_state *state,
641 struct xfs_da_state_blk *oldblk,
642 struct xfs_da_state_blk *newblk,
643 struct xfs_da_state_blk *addblk,
644 int treelevel,
645 int *result)
646{
647 struct xfs_da_intnode *node;
648 struct xfs_da3_icnode_hdr nodehdr;
649 xfs_dablk_t blkno;
650 int newcount;
651 int error;
652 int useextra;
653 struct xfs_inode *dp = state->args->dp;
654
655 trace_xfs_da_node_split(state->args);
656
657 node = oldblk->bp->b_addr;
658 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
659
660 /*
661 * With V2 dirs the extra block is data or freespace.
662 */
663 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
664 newcount = 1 + useextra;
665 /*
666 * Do we have to split the node?
667 */
668 if (nodehdr.count + newcount > state->args->geo->node_ents) {
669 /*
670 * Allocate a new node, add to the doubly linked chain of
671 * nodes, then move some of our excess entries into it.
672 */
673 error = xfs_da_grow_inode(state->args, &blkno);
674 if (error)
675 return error; /* GROT: dir is inconsistent */
676
677 error = xfs_da3_node_create(state->args, blkno, treelevel,
678 &newblk->bp, state->args->whichfork);
679 if (error)
680 return error; /* GROT: dir is inconsistent */
681 newblk->blkno = blkno;
682 newblk->magic = XFS_DA_NODE_MAGIC;
683 xfs_da3_node_rebalance(state, oldblk, newblk);
684 error = xfs_da3_blk_link(state, oldblk, newblk);
685 if (error)
686 return error;
687 *result = 1;
688 } else {
689 *result = 0;
690 }
691
692 /*
693 * Insert the new entry(s) into the correct block
694 * (updating last hashval in the process).
695 *
696 * xfs_da3_node_add() inserts BEFORE the given index,
697 * and as a result of using node_lookup_int() we always
698 * point to a valid entry (not after one), but a split
699 * operation always results in a new block whose hashvals
700 * FOLLOW the current block.
701 *
702 * If we had double-split op below us, then add the extra block too.
703 */
704 node = oldblk->bp->b_addr;
705 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
706 if (oldblk->index <= nodehdr.count) {
707 oldblk->index++;
708 xfs_da3_node_add(state, oldblk, addblk);
709 if (useextra) {
710 if (state->extraafter)
711 oldblk->index++;
712 xfs_da3_node_add(state, oldblk, &state->extrablk);
713 state->extravalid = 0;
714 }
715 } else {
716 newblk->index++;
717 xfs_da3_node_add(state, newblk, addblk);
718 if (useextra) {
719 if (state->extraafter)
720 newblk->index++;
721 xfs_da3_node_add(state, newblk, &state->extrablk);
722 state->extravalid = 0;
723 }
724 }
725
726 return 0;
727}
728
729/*
730 * Balance the btree elements between two intermediate nodes,
731 * usually one full and one empty.
732 *
733 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
734 */
735STATIC void
736xfs_da3_node_rebalance(
737 struct xfs_da_state *state,
738 struct xfs_da_state_blk *blk1,
739 struct xfs_da_state_blk *blk2)
740{
741 struct xfs_da_intnode *node1;
742 struct xfs_da_intnode *node2;
743 struct xfs_da_intnode *tmpnode;
744 struct xfs_da_node_entry *btree1;
745 struct xfs_da_node_entry *btree2;
746 struct xfs_da_node_entry *btree_s;
747 struct xfs_da_node_entry *btree_d;
748 struct xfs_da3_icnode_hdr nodehdr1;
749 struct xfs_da3_icnode_hdr nodehdr2;
750 struct xfs_trans *tp;
751 int count;
752 int tmp;
753 int swap = 0;
754 struct xfs_inode *dp = state->args->dp;
755
756 trace_xfs_da_node_rebalance(state->args);
757
758 node1 = blk1->bp->b_addr;
759 node2 = blk2->bp->b_addr;
760 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
761 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
762 btree1 = dp->d_ops->node_tree_p(node1);
763 btree2 = dp->d_ops->node_tree_p(node2);
764
765 /*
766 * Figure out how many entries need to move, and in which direction.
767 * Swap the nodes around if that makes it simpler.
768 */
769 if (nodehdr1.count > 0 && nodehdr2.count > 0 &&
770 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
771 (be32_to_cpu(btree2[nodehdr2.count - 1].hashval) <
772 be32_to_cpu(btree1[nodehdr1.count - 1].hashval)))) {
773 tmpnode = node1;
774 node1 = node2;
775 node2 = tmpnode;
776 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
777 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
778 btree1 = dp->d_ops->node_tree_p(node1);
779 btree2 = dp->d_ops->node_tree_p(node2);
780 swap = 1;
781 }
782
783 count = (nodehdr1.count - nodehdr2.count) / 2;
784 if (count == 0)
785 return;
786 tp = state->args->trans;
787 /*
788 * Two cases: high-to-low and low-to-high.
789 */
790 if (count > 0) {
791 /*
792 * Move elements in node2 up to make a hole.
793 */
794 tmp = nodehdr2.count;
795 if (tmp > 0) {
796 tmp *= (uint)sizeof(xfs_da_node_entry_t);
797 btree_s = &btree2[0];
798 btree_d = &btree2[count];
799 memmove(btree_d, btree_s, tmp);
800 }
801
802 /*
803 * Move the req'd B-tree elements from high in node1 to
804 * low in node2.
805 */
806 nodehdr2.count += count;
807 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
808 btree_s = &btree1[nodehdr1.count - count];
809 btree_d = &btree2[0];
810 memcpy(btree_d, btree_s, tmp);
811 nodehdr1.count -= count;
812 } else {
813 /*
814 * Move the req'd B-tree elements from low in node2 to
815 * high in node1.
816 */
817 count = -count;
818 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
819 btree_s = &btree2[0];
820 btree_d = &btree1[nodehdr1.count];
821 memcpy(btree_d, btree_s, tmp);
822 nodehdr1.count += count;
823
824 xfs_trans_log_buf(tp, blk1->bp,
825 XFS_DA_LOGRANGE(node1, btree_d, tmp));
826
827 /*
828 * Move elements in node2 down to fill the hole.
829 */
830 tmp = nodehdr2.count - count;
831 tmp *= (uint)sizeof(xfs_da_node_entry_t);
832 btree_s = &btree2[count];
833 btree_d = &btree2[0];
834 memmove(btree_d, btree_s, tmp);
835 nodehdr2.count -= count;
836 }
837
838 /*
839 * Log header of node 1 and all current bits of node 2.
840 */
841 dp->d_ops->node_hdr_to_disk(node1, &nodehdr1);
842 xfs_trans_log_buf(tp, blk1->bp,
843 XFS_DA_LOGRANGE(node1, &node1->hdr, dp->d_ops->node_hdr_size));
844
845 dp->d_ops->node_hdr_to_disk(node2, &nodehdr2);
846 xfs_trans_log_buf(tp, blk2->bp,
847 XFS_DA_LOGRANGE(node2, &node2->hdr,
848 dp->d_ops->node_hdr_size +
849 (sizeof(btree2[0]) * nodehdr2.count)));
850
851 /*
852 * Record the last hashval from each block for upward propagation.
853 * (note: don't use the swapped node pointers)
854 */
855 if (swap) {
856 node1 = blk1->bp->b_addr;
857 node2 = blk2->bp->b_addr;
858 dp->d_ops->node_hdr_from_disk(&nodehdr1, node1);
859 dp->d_ops->node_hdr_from_disk(&nodehdr2, node2);
860 btree1 = dp->d_ops->node_tree_p(node1);
861 btree2 = dp->d_ops->node_tree_p(node2);
862 }
863 blk1->hashval = be32_to_cpu(btree1[nodehdr1.count - 1].hashval);
864 blk2->hashval = be32_to_cpu(btree2[nodehdr2.count - 1].hashval);
865
866 /*
867 * Adjust the expected index for insertion.
868 */
869 if (blk1->index >= nodehdr1.count) {
870 blk2->index = blk1->index - nodehdr1.count;
871 blk1->index = nodehdr1.count + 1; /* make it invalid */
872 }
873}
874
875/*
876 * Add a new entry to an intermediate node.
877 */
878STATIC void
879xfs_da3_node_add(
880 struct xfs_da_state *state,
881 struct xfs_da_state_blk *oldblk,
882 struct xfs_da_state_blk *newblk)
883{
884 struct xfs_da_intnode *node;
885 struct xfs_da3_icnode_hdr nodehdr;
886 struct xfs_da_node_entry *btree;
887 int tmp;
888 struct xfs_inode *dp = state->args->dp;
889
890 trace_xfs_da_node_add(state->args);
891
892 node = oldblk->bp->b_addr;
893 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
894 btree = dp->d_ops->node_tree_p(node);
895
896 ASSERT(oldblk->index >= 0 && oldblk->index <= nodehdr.count);
897 ASSERT(newblk->blkno != 0);
898 if (state->args->whichfork == XFS_DATA_FORK)
899 ASSERT(newblk->blkno >= state->args->geo->leafblk &&
900 newblk->blkno < state->args->geo->freeblk);
901
902 /*
903 * We may need to make some room before we insert the new node.
904 */
905 tmp = 0;
906 if (oldblk->index < nodehdr.count) {
907 tmp = (nodehdr.count - oldblk->index) * (uint)sizeof(*btree);
908 memmove(&btree[oldblk->index + 1], &btree[oldblk->index], tmp);
909 }
910 btree[oldblk->index].hashval = cpu_to_be32(newblk->hashval);
911 btree[oldblk->index].before = cpu_to_be32(newblk->blkno);
912 xfs_trans_log_buf(state->args->trans, oldblk->bp,
913 XFS_DA_LOGRANGE(node, &btree[oldblk->index],
914 tmp + sizeof(*btree)));
915
916 nodehdr.count += 1;
917 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
918 xfs_trans_log_buf(state->args->trans, oldblk->bp,
919 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
920
921 /*
922 * Copy the last hash value from the oldblk to propagate upwards.
923 */
924 oldblk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
925}
926
927/*========================================================================
928 * Routines used for shrinking the Btree.
929 *========================================================================*/
930
931/*
932 * Deallocate an empty leaf node, remove it from its parent,
933 * possibly deallocating that block, etc...
934 */
935int
936xfs_da3_join(
937 struct xfs_da_state *state)
938{
939 struct xfs_da_state_blk *drop_blk;
940 struct xfs_da_state_blk *save_blk;
941 int action = 0;
942 int error;
943
944 trace_xfs_da_join(state->args);
945
946 drop_blk = &state->path.blk[ state->path.active-1 ];
947 save_blk = &state->altpath.blk[ state->path.active-1 ];
948 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
949 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
950 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
951
952 /*
953 * Walk back up the tree joining/deallocating as necessary.
954 * When we stop dropping blocks, break out.
955 */
956 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
957 state->path.active--) {
958 /*
959 * See if we can combine the block with a neighbor.
960 * (action == 0) => no options, just leave
961 * (action == 1) => coalesce, then unlink
962 * (action == 2) => block empty, unlink it
963 */
964 switch (drop_blk->magic) {
965 case XFS_ATTR_LEAF_MAGIC:
966 error = xfs_attr3_leaf_toosmall(state, &action);
967 if (error)
968 return error;
969 if (action == 0)
970 return 0;
971 xfs_attr3_leaf_unbalance(state, drop_blk, save_blk);
972 break;
973 case XFS_DIR2_LEAFN_MAGIC:
974 error = xfs_dir2_leafn_toosmall(state, &action);
975 if (error)
976 return error;
977 if (action == 0)
978 return 0;
979 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
980 break;
981 case XFS_DA_NODE_MAGIC:
982 /*
983 * Remove the offending node, fixup hashvals,
984 * check for a toosmall neighbor.
985 */
986 xfs_da3_node_remove(state, drop_blk);
987 xfs_da3_fixhashpath(state, &state->path);
988 error = xfs_da3_node_toosmall(state, &action);
989 if (error)
990 return error;
991 if (action == 0)
992 return 0;
993 xfs_da3_node_unbalance(state, drop_blk, save_blk);
994 break;
995 }
996 xfs_da3_fixhashpath(state, &state->altpath);
997 error = xfs_da3_blk_unlink(state, drop_blk, save_blk);
998 xfs_da_state_kill_altpath(state);
999 if (error)
1000 return error;
1001 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
1002 drop_blk->bp);
1003 drop_blk->bp = NULL;
1004 if (error)
1005 return error;
1006 }
1007 /*
1008 * We joined all the way to the top. If it turns out that
1009 * we only have one entry in the root, make the child block
1010 * the new root.
1011 */
1012 xfs_da3_node_remove(state, drop_blk);
1013 xfs_da3_fixhashpath(state, &state->path);
1014 error = xfs_da3_root_join(state, &state->path.blk[0]);
1015 return error;
1016}
1017
1018#ifdef DEBUG
1019static void
1020xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
1021{
1022 __be16 magic = blkinfo->magic;
1023
1024 if (level == 1) {
1025 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1026 magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1027 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1028 magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1029 } else {
1030 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1031 magic == cpu_to_be16(XFS_DA3_NODE_MAGIC));
1032 }
1033 ASSERT(!blkinfo->forw);
1034 ASSERT(!blkinfo->back);
1035}
1036#else /* !DEBUG */
1037#define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
1038#endif /* !DEBUG */
1039
1040/*
1041 * We have only one entry in the root. Copy the only remaining child of
1042 * the old root to block 0 as the new root node.
1043 */
1044STATIC int
1045xfs_da3_root_join(
1046 struct xfs_da_state *state,
1047 struct xfs_da_state_blk *root_blk)
1048{
1049 struct xfs_da_intnode *oldroot;
1050 struct xfs_da_args *args;
1051 xfs_dablk_t child;
1052 struct xfs_buf *bp;
1053 struct xfs_da3_icnode_hdr oldroothdr;
1054 struct xfs_da_node_entry *btree;
1055 int error;
1056 struct xfs_inode *dp = state->args->dp;
1057
1058 trace_xfs_da_root_join(state->args);
1059
1060 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
1061
1062 args = state->args;
1063 oldroot = root_blk->bp->b_addr;
1064 dp->d_ops->node_hdr_from_disk(&oldroothdr, oldroot);
1065 ASSERT(oldroothdr.forw == 0);
1066 ASSERT(oldroothdr.back == 0);
1067
1068 /*
1069 * If the root has more than one child, then don't do anything.
1070 */
1071 if (oldroothdr.count > 1)
1072 return 0;
1073
1074 /*
1075 * Read in the (only) child block, then copy those bytes into
1076 * the root block's buffer and free the original child block.
1077 */
1078 btree = dp->d_ops->node_tree_p(oldroot);
1079 child = be32_to_cpu(btree[0].before);
1080 ASSERT(child != 0);
1081 error = xfs_da3_node_read(args->trans, dp, child, -1, &bp,
1082 args->whichfork);
1083 if (error)
1084 return error;
1085 xfs_da_blkinfo_onlychild_validate(bp->b_addr, oldroothdr.level);
1086
1087 /*
1088 * This could be copying a leaf back into the root block in the case of
1089 * there only being a single leaf block left in the tree. Hence we have
1090 * to update the b_ops pointer as well to match the buffer type change
1091 * that could occur. For dir3 blocks we also need to update the block
1092 * number in the buffer header.
1093 */
1094 memcpy(root_blk->bp->b_addr, bp->b_addr, args->geo->blksize);
1095 root_blk->bp->b_ops = bp->b_ops;
1096 xfs_trans_buf_copy_type(root_blk->bp, bp);
1097 if (oldroothdr.magic == XFS_DA3_NODE_MAGIC) {
1098 struct xfs_da3_blkinfo *da3 = root_blk->bp->b_addr;
1099 da3->blkno = cpu_to_be64(root_blk->bp->b_bn);
1100 }
1101 xfs_trans_log_buf(args->trans, root_blk->bp, 0,
1102 args->geo->blksize - 1);
1103 error = xfs_da_shrink_inode(args, child, bp);
1104 return error;
1105}
1106
1107/*
1108 * Check a node block and its neighbors to see if the block should be
1109 * collapsed into one or the other neighbor. Always keep the block
1110 * with the smaller block number.
1111 * If the current block is over 50% full, don't try to join it, return 0.
1112 * If the block is empty, fill in the state structure and return 2.
1113 * If it can be collapsed, fill in the state structure and return 1.
1114 * If nothing can be done, return 0.
1115 */
1116STATIC int
1117xfs_da3_node_toosmall(
1118 struct xfs_da_state *state,
1119 int *action)
1120{
1121 struct xfs_da_intnode *node;
1122 struct xfs_da_state_blk *blk;
1123 struct xfs_da_blkinfo *info;
1124 xfs_dablk_t blkno;
1125 struct xfs_buf *bp;
1126 struct xfs_da3_icnode_hdr nodehdr;
1127 int count;
1128 int forward;
1129 int error;
1130 int retval;
1131 int i;
1132 struct xfs_inode *dp = state->args->dp;
1133
1134 trace_xfs_da_node_toosmall(state->args);
1135
1136 /*
1137 * Check for the degenerate case of the block being over 50% full.
1138 * If so, it's not worth even looking to see if we might be able
1139 * to coalesce with a sibling.
1140 */
1141 blk = &state->path.blk[ state->path.active-1 ];
1142 info = blk->bp->b_addr;
1143 node = (xfs_da_intnode_t *)info;
1144 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1145 if (nodehdr.count > (state->args->geo->node_ents >> 1)) {
1146 *action = 0; /* blk over 50%, don't try to join */
1147 return 0; /* blk over 50%, don't try to join */
1148 }
1149
1150 /*
1151 * Check for the degenerate case of the block being empty.
1152 * If the block is empty, we'll simply delete it, no need to
1153 * coalesce it with a sibling block. We choose (arbitrarily)
1154 * to merge with the forward block unless it is NULL.
1155 */
1156 if (nodehdr.count == 0) {
1157 /*
1158 * Make altpath point to the block we want to keep and
1159 * path point to the block we want to drop (this one).
1160 */
1161 forward = (info->forw != 0);
1162 memcpy(&state->altpath, &state->path, sizeof(state->path));
1163 error = xfs_da3_path_shift(state, &state->altpath, forward,
1164 0, &retval);
1165 if (error)
1166 return error;
1167 if (retval) {
1168 *action = 0;
1169 } else {
1170 *action = 2;
1171 }
1172 return 0;
1173 }
1174
1175 /*
1176 * Examine each sibling block to see if we can coalesce with
1177 * at least 25% free space to spare. We need to figure out
1178 * whether to merge with the forward or the backward block.
1179 * We prefer coalescing with the lower numbered sibling so as
1180 * to shrink a directory over time.
1181 */
1182 count = state->args->geo->node_ents;
1183 count -= state->args->geo->node_ents >> 2;
1184 count -= nodehdr.count;
1185
1186 /* start with smaller blk num */
1187 forward = nodehdr.forw < nodehdr.back;
1188 for (i = 0; i < 2; forward = !forward, i++) {
1189 struct xfs_da3_icnode_hdr thdr;
1190 if (forward)
1191 blkno = nodehdr.forw;
1192 else
1193 blkno = nodehdr.back;
1194 if (blkno == 0)
1195 continue;
1196 error = xfs_da3_node_read(state->args->trans, dp,
1197 blkno, -1, &bp, state->args->whichfork);
1198 if (error)
1199 return error;
1200
1201 node = bp->b_addr;
1202 dp->d_ops->node_hdr_from_disk(&thdr, node);
1203 xfs_trans_brelse(state->args->trans, bp);
1204
1205 if (count - thdr.count >= 0)
1206 break; /* fits with at least 25% to spare */
1207 }
1208 if (i >= 2) {
1209 *action = 0;
1210 return 0;
1211 }
1212
1213 /*
1214 * Make altpath point to the block we want to keep (the lower
1215 * numbered block) and path point to the block we want to drop.
1216 */
1217 memcpy(&state->altpath, &state->path, sizeof(state->path));
1218 if (blkno < blk->blkno) {
1219 error = xfs_da3_path_shift(state, &state->altpath, forward,
1220 0, &retval);
1221 } else {
1222 error = xfs_da3_path_shift(state, &state->path, forward,
1223 0, &retval);
1224 }
1225 if (error)
1226 return error;
1227 if (retval) {
1228 *action = 0;
1229 return 0;
1230 }
1231 *action = 1;
1232 return 0;
1233}
1234
1235/*
1236 * Pick up the last hashvalue from an intermediate node.
1237 */
1238STATIC uint
1239xfs_da3_node_lasthash(
1240 struct xfs_inode *dp,
1241 struct xfs_buf *bp,
1242 int *count)
1243{
1244 struct xfs_da_intnode *node;
1245 struct xfs_da_node_entry *btree;
1246 struct xfs_da3_icnode_hdr nodehdr;
1247
1248 node = bp->b_addr;
1249 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1250 if (count)
1251 *count = nodehdr.count;
1252 if (!nodehdr.count)
1253 return 0;
1254 btree = dp->d_ops->node_tree_p(node);
1255 return be32_to_cpu(btree[nodehdr.count - 1].hashval);
1256}
1257
1258/*
1259 * Walk back up the tree adjusting hash values as necessary,
1260 * when we stop making changes, return.
1261 */
1262void
1263xfs_da3_fixhashpath(
1264 struct xfs_da_state *state,
1265 struct xfs_da_state_path *path)
1266{
1267 struct xfs_da_state_blk *blk;
1268 struct xfs_da_intnode *node;
1269 struct xfs_da_node_entry *btree;
1270 xfs_dahash_t lasthash=0;
1271 int level;
1272 int count;
1273 struct xfs_inode *dp = state->args->dp;
1274
1275 trace_xfs_da_fixhashpath(state->args);
1276
1277 level = path->active-1;
1278 blk = &path->blk[ level ];
1279 switch (blk->magic) {
1280 case XFS_ATTR_LEAF_MAGIC:
1281 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
1282 if (count == 0)
1283 return;
1284 break;
1285 case XFS_DIR2_LEAFN_MAGIC:
1286 lasthash = xfs_dir2_leafn_lasthash(dp, blk->bp, &count);
1287 if (count == 0)
1288 return;
1289 break;
1290 case XFS_DA_NODE_MAGIC:
1291 lasthash = xfs_da3_node_lasthash(dp, blk->bp, &count);
1292 if (count == 0)
1293 return;
1294 break;
1295 }
1296 for (blk--, level--; level >= 0; blk--, level--) {
1297 struct xfs_da3_icnode_hdr nodehdr;
1298
1299 node = blk->bp->b_addr;
1300 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1301 btree = dp->d_ops->node_tree_p(node);
1302 if (be32_to_cpu(btree[blk->index].hashval) == lasthash)
1303 break;
1304 blk->hashval = lasthash;
1305 btree[blk->index].hashval = cpu_to_be32(lasthash);
1306 xfs_trans_log_buf(state->args->trans, blk->bp,
1307 XFS_DA_LOGRANGE(node, &btree[blk->index],
1308 sizeof(*btree)));
1309
1310 lasthash = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1311 }
1312}
1313
1314/*
1315 * Remove an entry from an intermediate node.
1316 */
1317STATIC void
1318xfs_da3_node_remove(
1319 struct xfs_da_state *state,
1320 struct xfs_da_state_blk *drop_blk)
1321{
1322 struct xfs_da_intnode *node;
1323 struct xfs_da3_icnode_hdr nodehdr;
1324 struct xfs_da_node_entry *btree;
1325 int index;
1326 int tmp;
1327 struct xfs_inode *dp = state->args->dp;
1328
1329 trace_xfs_da_node_remove(state->args);
1330
1331 node = drop_blk->bp->b_addr;
1332 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1333 ASSERT(drop_blk->index < nodehdr.count);
1334 ASSERT(drop_blk->index >= 0);
1335
1336 /*
1337 * Copy over the offending entry, or just zero it out.
1338 */
1339 index = drop_blk->index;
1340 btree = dp->d_ops->node_tree_p(node);
1341 if (index < nodehdr.count - 1) {
1342 tmp = nodehdr.count - index - 1;
1343 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1344 memmove(&btree[index], &btree[index + 1], tmp);
1345 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1346 XFS_DA_LOGRANGE(node, &btree[index], tmp));
1347 index = nodehdr.count - 1;
1348 }
1349 memset(&btree[index], 0, sizeof(xfs_da_node_entry_t));
1350 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1351 XFS_DA_LOGRANGE(node, &btree[index], sizeof(btree[index])));
1352 nodehdr.count -= 1;
1353 dp->d_ops->node_hdr_to_disk(node, &nodehdr);
1354 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
1355 XFS_DA_LOGRANGE(node, &node->hdr, dp->d_ops->node_hdr_size));
1356
1357 /*
1358 * Copy the last hash value from the block to propagate upwards.
1359 */
1360 drop_blk->hashval = be32_to_cpu(btree[index - 1].hashval);
1361}
1362
1363/*
1364 * Unbalance the elements between two intermediate nodes,
1365 * move all Btree elements from one node into another.
1366 */
1367STATIC void
1368xfs_da3_node_unbalance(
1369 struct xfs_da_state *state,
1370 struct xfs_da_state_blk *drop_blk,
1371 struct xfs_da_state_blk *save_blk)
1372{
1373 struct xfs_da_intnode *drop_node;
1374 struct xfs_da_intnode *save_node;
1375 struct xfs_da_node_entry *drop_btree;
1376 struct xfs_da_node_entry *save_btree;
1377 struct xfs_da3_icnode_hdr drop_hdr;
1378 struct xfs_da3_icnode_hdr save_hdr;
1379 struct xfs_trans *tp;
1380 int sindex;
1381 int tmp;
1382 struct xfs_inode *dp = state->args->dp;
1383
1384 trace_xfs_da_node_unbalance(state->args);
1385
1386 drop_node = drop_blk->bp->b_addr;
1387 save_node = save_blk->bp->b_addr;
1388 dp->d_ops->node_hdr_from_disk(&drop_hdr, drop_node);
1389 dp->d_ops->node_hdr_from_disk(&save_hdr, save_node);
1390 drop_btree = dp->d_ops->node_tree_p(drop_node);
1391 save_btree = dp->d_ops->node_tree_p(save_node);
1392 tp = state->args->trans;
1393
1394 /*
1395 * If the dying block has lower hashvals, then move all the
1396 * elements in the remaining block up to make a hole.
1397 */
1398 if ((be32_to_cpu(drop_btree[0].hashval) <
1399 be32_to_cpu(save_btree[0].hashval)) ||
1400 (be32_to_cpu(drop_btree[drop_hdr.count - 1].hashval) <
1401 be32_to_cpu(save_btree[save_hdr.count - 1].hashval))) {
1402 /* XXX: check this - is memmove dst correct? */
1403 tmp = save_hdr.count * sizeof(xfs_da_node_entry_t);
1404 memmove(&save_btree[drop_hdr.count], &save_btree[0], tmp);
1405
1406 sindex = 0;
1407 xfs_trans_log_buf(tp, save_blk->bp,
1408 XFS_DA_LOGRANGE(save_node, &save_btree[0],
1409 (save_hdr.count + drop_hdr.count) *
1410 sizeof(xfs_da_node_entry_t)));
1411 } else {
1412 sindex = save_hdr.count;
1413 xfs_trans_log_buf(tp, save_blk->bp,
1414 XFS_DA_LOGRANGE(save_node, &save_btree[sindex],
1415 drop_hdr.count * sizeof(xfs_da_node_entry_t)));
1416 }
1417
1418 /*
1419 * Move all the B-tree elements from drop_blk to save_blk.
1420 */
1421 tmp = drop_hdr.count * (uint)sizeof(xfs_da_node_entry_t);
1422 memcpy(&save_btree[sindex], &drop_btree[0], tmp);
1423 save_hdr.count += drop_hdr.count;
1424
1425 dp->d_ops->node_hdr_to_disk(save_node, &save_hdr);
1426 xfs_trans_log_buf(tp, save_blk->bp,
1427 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1428 dp->d_ops->node_hdr_size));
1429
1430 /*
1431 * Save the last hashval in the remaining block for upward propagation.
1432 */
1433 save_blk->hashval = be32_to_cpu(save_btree[save_hdr.count - 1].hashval);
1434}
1435
1436/*========================================================================
1437 * Routines used for finding things in the Btree.
1438 *========================================================================*/
1439
1440/*
1441 * Walk down the Btree looking for a particular filename, filling
1442 * in the state structure as we go.
1443 *
1444 * We will set the state structure to point to each of the elements
1445 * in each of the nodes where either the hashval is or should be.
1446 *
1447 * We support duplicate hashval's so for each entry in the current
1448 * node that could contain the desired hashval, descend. This is a
1449 * pruned depth-first tree search.
1450 */
1451int /* error */
1452xfs_da3_node_lookup_int(
1453 struct xfs_da_state *state,
1454 int *result)
1455{
1456 struct xfs_da_state_blk *blk;
1457 struct xfs_da_blkinfo *curr;
1458 struct xfs_da_intnode *node;
1459 struct xfs_da_node_entry *btree;
1460 struct xfs_da3_icnode_hdr nodehdr;
1461 struct xfs_da_args *args;
1462 xfs_dablk_t blkno;
1463 xfs_dahash_t hashval;
1464 xfs_dahash_t btreehashval;
1465 int probe;
1466 int span;
1467 int max;
1468 int error;
1469 int retval;
1470 struct xfs_inode *dp = state->args->dp;
1471
1472 args = state->args;
1473
1474 /*
1475 * Descend thru the B-tree searching each level for the right
1476 * node to use, until the right hashval is found.
1477 */
1478 blkno = (args->whichfork == XFS_DATA_FORK)? args->geo->leafblk : 0;
1479 for (blk = &state->path.blk[0], state->path.active = 1;
1480 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1481 blk++, state->path.active++) {
1482 /*
1483 * Read the next node down in the tree.
1484 */
1485 blk->blkno = blkno;
1486 error = xfs_da3_node_read(args->trans, args->dp, blkno,
1487 -1, &blk->bp, args->whichfork);
1488 if (error) {
1489 blk->blkno = 0;
1490 state->path.active--;
1491 return error;
1492 }
1493 curr = blk->bp->b_addr;
1494 blk->magic = be16_to_cpu(curr->magic);
1495
1496 if (blk->magic == XFS_ATTR_LEAF_MAGIC ||
1497 blk->magic == XFS_ATTR3_LEAF_MAGIC) {
1498 blk->magic = XFS_ATTR_LEAF_MAGIC;
1499 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1500 break;
1501 }
1502
1503 if (blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1504 blk->magic == XFS_DIR3_LEAFN_MAGIC) {
1505 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1506 blk->hashval = xfs_dir2_leafn_lasthash(args->dp,
1507 blk->bp, NULL);
1508 break;
1509 }
1510
1511 blk->magic = XFS_DA_NODE_MAGIC;
1512
1513
1514 /*
1515 * Search an intermediate node for a match.
1516 */
1517 node = blk->bp->b_addr;
1518 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1519 btree = dp->d_ops->node_tree_p(node);
1520
1521 max = nodehdr.count;
1522 blk->hashval = be32_to_cpu(btree[max - 1].hashval);
1523
1524 /*
1525 * Binary search. (note: small blocks will skip loop)
1526 */
1527 probe = span = max / 2;
1528 hashval = args->hashval;
1529 while (span > 4) {
1530 span /= 2;
1531 btreehashval = be32_to_cpu(btree[probe].hashval);
1532 if (btreehashval < hashval)
1533 probe += span;
1534 else if (btreehashval > hashval)
1535 probe -= span;
1536 else
1537 break;
1538 }
1539 ASSERT((probe >= 0) && (probe < max));
1540 ASSERT((span <= 4) ||
1541 (be32_to_cpu(btree[probe].hashval) == hashval));
1542
1543 /*
1544 * Since we may have duplicate hashval's, find the first
1545 * matching hashval in the node.
1546 */
1547 while (probe > 0 &&
1548 be32_to_cpu(btree[probe].hashval) >= hashval) {
1549 probe--;
1550 }
1551 while (probe < max &&
1552 be32_to_cpu(btree[probe].hashval) < hashval) {
1553 probe++;
1554 }
1555
1556 /*
1557 * Pick the right block to descend on.
1558 */
1559 if (probe == max) {
1560 blk->index = max - 1;
1561 blkno = be32_to_cpu(btree[max - 1].before);
1562 } else {
1563 blk->index = probe;
1564 blkno = be32_to_cpu(btree[probe].before);
1565 }
1566 }
1567
1568 /*
1569 * A leaf block that ends in the hashval that we are interested in
1570 * (final hashval == search hashval) means that the next block may
1571 * contain more entries with the same hashval, shift upward to the
1572 * next leaf and keep searching.
1573 */
1574 for (;;) {
1575 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1576 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1577 &blk->index, state);
1578 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1579 retval = xfs_attr3_leaf_lookup_int(blk->bp, args);
1580 blk->index = args->index;
1581 args->blkno = blk->blkno;
1582 } else {
1583 ASSERT(0);
1584 return -EFSCORRUPTED;
1585 }
1586 if (((retval == -ENOENT) || (retval == -ENOATTR)) &&
1587 (blk->hashval == args->hashval)) {
1588 error = xfs_da3_path_shift(state, &state->path, 1, 1,
1589 &retval);
1590 if (error)
1591 return error;
1592 if (retval == 0) {
1593 continue;
1594 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1595 /* path_shift() gives ENOENT */
1596 retval = -ENOATTR;
1597 }
1598 }
1599 break;
1600 }
1601 *result = retval;
1602 return 0;
1603}
1604
1605/*========================================================================
1606 * Utility routines.
1607 *========================================================================*/
1608
1609/*
1610 * Compare two intermediate nodes for "order".
1611 */
1612STATIC int
1613xfs_da3_node_order(
1614 struct xfs_inode *dp,
1615 struct xfs_buf *node1_bp,
1616 struct xfs_buf *node2_bp)
1617{
1618 struct xfs_da_intnode *node1;
1619 struct xfs_da_intnode *node2;
1620 struct xfs_da_node_entry *btree1;
1621 struct xfs_da_node_entry *btree2;
1622 struct xfs_da3_icnode_hdr node1hdr;
1623 struct xfs_da3_icnode_hdr node2hdr;
1624
1625 node1 = node1_bp->b_addr;
1626 node2 = node2_bp->b_addr;
1627 dp->d_ops->node_hdr_from_disk(&node1hdr, node1);
1628 dp->d_ops->node_hdr_from_disk(&node2hdr, node2);
1629 btree1 = dp->d_ops->node_tree_p(node1);
1630 btree2 = dp->d_ops->node_tree_p(node2);
1631
1632 if (node1hdr.count > 0 && node2hdr.count > 0 &&
1633 ((be32_to_cpu(btree2[0].hashval) < be32_to_cpu(btree1[0].hashval)) ||
1634 (be32_to_cpu(btree2[node2hdr.count - 1].hashval) <
1635 be32_to_cpu(btree1[node1hdr.count - 1].hashval)))) {
1636 return 1;
1637 }
1638 return 0;
1639}
1640
1641/*
1642 * Link a new block into a doubly linked list of blocks (of whatever type).
1643 */
1644int /* error */
1645xfs_da3_blk_link(
1646 struct xfs_da_state *state,
1647 struct xfs_da_state_blk *old_blk,
1648 struct xfs_da_state_blk *new_blk)
1649{
1650 struct xfs_da_blkinfo *old_info;
1651 struct xfs_da_blkinfo *new_info;
1652 struct xfs_da_blkinfo *tmp_info;
1653 struct xfs_da_args *args;
1654 struct xfs_buf *bp;
1655 int before = 0;
1656 int error;
1657 struct xfs_inode *dp = state->args->dp;
1658
1659 /*
1660 * Set up environment.
1661 */
1662 args = state->args;
1663 ASSERT(args != NULL);
1664 old_info = old_blk->bp->b_addr;
1665 new_info = new_blk->bp->b_addr;
1666 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1667 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1668 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1669
1670 switch (old_blk->magic) {
1671 case XFS_ATTR_LEAF_MAGIC:
1672 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1673 break;
1674 case XFS_DIR2_LEAFN_MAGIC:
1675 before = xfs_dir2_leafn_order(dp, old_blk->bp, new_blk->bp);
1676 break;
1677 case XFS_DA_NODE_MAGIC:
1678 before = xfs_da3_node_order(dp, old_blk->bp, new_blk->bp);
1679 break;
1680 }
1681
1682 /*
1683 * Link blocks in appropriate order.
1684 */
1685 if (before) {
1686 /*
1687 * Link new block in before existing block.
1688 */
1689 trace_xfs_da_link_before(args);
1690 new_info->forw = cpu_to_be32(old_blk->blkno);
1691 new_info->back = old_info->back;
1692 if (old_info->back) {
1693 error = xfs_da3_node_read(args->trans, dp,
1694 be32_to_cpu(old_info->back),
1695 -1, &bp, args->whichfork);
1696 if (error)
1697 return error;
1698 ASSERT(bp != NULL);
1699 tmp_info = bp->b_addr;
1700 ASSERT(tmp_info->magic == old_info->magic);
1701 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1702 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1703 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1704 }
1705 old_info->back = cpu_to_be32(new_blk->blkno);
1706 } else {
1707 /*
1708 * Link new block in after existing block.
1709 */
1710 trace_xfs_da_link_after(args);
1711 new_info->forw = old_info->forw;
1712 new_info->back = cpu_to_be32(old_blk->blkno);
1713 if (old_info->forw) {
1714 error = xfs_da3_node_read(args->trans, dp,
1715 be32_to_cpu(old_info->forw),
1716 -1, &bp, args->whichfork);
1717 if (error)
1718 return error;
1719 ASSERT(bp != NULL);
1720 tmp_info = bp->b_addr;
1721 ASSERT(tmp_info->magic == old_info->magic);
1722 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1723 tmp_info->back = cpu_to_be32(new_blk->blkno);
1724 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1725 }
1726 old_info->forw = cpu_to_be32(new_blk->blkno);
1727 }
1728
1729 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1730 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1731 return 0;
1732}
1733
1734/*
1735 * Unlink a block from a doubly linked list of blocks.
1736 */
1737STATIC int /* error */
1738xfs_da3_blk_unlink(
1739 struct xfs_da_state *state,
1740 struct xfs_da_state_blk *drop_blk,
1741 struct xfs_da_state_blk *save_blk)
1742{
1743 struct xfs_da_blkinfo *drop_info;
1744 struct xfs_da_blkinfo *save_info;
1745 struct xfs_da_blkinfo *tmp_info;
1746 struct xfs_da_args *args;
1747 struct xfs_buf *bp;
1748 int error;
1749
1750 /*
1751 * Set up environment.
1752 */
1753 args = state->args;
1754 ASSERT(args != NULL);
1755 save_info = save_blk->bp->b_addr;
1756 drop_info = drop_blk->bp->b_addr;
1757 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1758 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1759 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1760 ASSERT(save_blk->magic == drop_blk->magic);
1761 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1762 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1763 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1764 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1765
1766 /*
1767 * Unlink the leaf block from the doubly linked chain of leaves.
1768 */
1769 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1770 trace_xfs_da_unlink_back(args);
1771 save_info->back = drop_info->back;
1772 if (drop_info->back) {
1773 error = xfs_da3_node_read(args->trans, args->dp,
1774 be32_to_cpu(drop_info->back),
1775 -1, &bp, args->whichfork);
1776 if (error)
1777 return error;
1778 ASSERT(bp != NULL);
1779 tmp_info = bp->b_addr;
1780 ASSERT(tmp_info->magic == save_info->magic);
1781 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1782 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1783 xfs_trans_log_buf(args->trans, bp, 0,
1784 sizeof(*tmp_info) - 1);
1785 }
1786 } else {
1787 trace_xfs_da_unlink_forward(args);
1788 save_info->forw = drop_info->forw;
1789 if (drop_info->forw) {
1790 error = xfs_da3_node_read(args->trans, args->dp,
1791 be32_to_cpu(drop_info->forw),
1792 -1, &bp, args->whichfork);
1793 if (error)
1794 return error;
1795 ASSERT(bp != NULL);
1796 tmp_info = bp->b_addr;
1797 ASSERT(tmp_info->magic == save_info->magic);
1798 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1799 tmp_info->back = cpu_to_be32(save_blk->blkno);
1800 xfs_trans_log_buf(args->trans, bp, 0,
1801 sizeof(*tmp_info) - 1);
1802 }
1803 }
1804
1805 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1806 return 0;
1807}
1808
1809/*
1810 * Move a path "forward" or "!forward" one block at the current level.
1811 *
1812 * This routine will adjust a "path" to point to the next block
1813 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1814 * Btree, including updating pointers to the intermediate nodes between
1815 * the new bottom and the root.
1816 */
1817int /* error */
1818xfs_da3_path_shift(
1819 struct xfs_da_state *state,
1820 struct xfs_da_state_path *path,
1821 int forward,
1822 int release,
1823 int *result)
1824{
1825 struct xfs_da_state_blk *blk;
1826 struct xfs_da_blkinfo *info;
1827 struct xfs_da_intnode *node;
1828 struct xfs_da_args *args;
1829 struct xfs_da_node_entry *btree;
1830 struct xfs_da3_icnode_hdr nodehdr;
1831 struct xfs_buf *bp;
1832 xfs_dablk_t blkno = 0;
1833 int level;
1834 int error;
1835 struct xfs_inode *dp = state->args->dp;
1836
1837 trace_xfs_da_path_shift(state->args);
1838
1839 /*
1840 * Roll up the Btree looking for the first block where our
1841 * current index is not at the edge of the block. Note that
1842 * we skip the bottom layer because we want the sibling block.
1843 */
1844 args = state->args;
1845 ASSERT(args != NULL);
1846 ASSERT(path != NULL);
1847 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1848 level = (path->active-1) - 1; /* skip bottom layer in path */
1849 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1850 node = blk->bp->b_addr;
1851 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1852 btree = dp->d_ops->node_tree_p(node);
1853
1854 if (forward && (blk->index < nodehdr.count - 1)) {
1855 blk->index++;
1856 blkno = be32_to_cpu(btree[blk->index].before);
1857 break;
1858 } else if (!forward && (blk->index > 0)) {
1859 blk->index--;
1860 blkno = be32_to_cpu(btree[blk->index].before);
1861 break;
1862 }
1863 }
1864 if (level < 0) {
1865 *result = -ENOENT; /* we're out of our tree */
1866 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1867 return 0;
1868 }
1869
1870 /*
1871 * Roll down the edge of the subtree until we reach the
1872 * same depth we were at originally.
1873 */
1874 for (blk++, level++; level < path->active; blk++, level++) {
1875 /*
1876 * Read the next child block into a local buffer.
1877 */
1878 error = xfs_da3_node_read(args->trans, dp, blkno, -1, &bp,
1879 args->whichfork);
1880 if (error)
1881 return error;
1882
1883 /*
1884 * Release the old block (if it's dirty, the trans doesn't
1885 * actually let go) and swap the local buffer into the path
1886 * structure. This ensures failure of the above read doesn't set
1887 * a NULL buffer in an active slot in the path.
1888 */
1889 if (release)
1890 xfs_trans_brelse(args->trans, blk->bp);
1891 blk->blkno = blkno;
1892 blk->bp = bp;
1893
1894 info = blk->bp->b_addr;
1895 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1896 info->magic == cpu_to_be16(XFS_DA3_NODE_MAGIC) ||
1897 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1898 info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC) ||
1899 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC) ||
1900 info->magic == cpu_to_be16(XFS_ATTR3_LEAF_MAGIC));
1901
1902
1903 /*
1904 * Note: we flatten the magic number to a single type so we
1905 * don't have to compare against crc/non-crc types elsewhere.
1906 */
1907 switch (be16_to_cpu(info->magic)) {
1908 case XFS_DA_NODE_MAGIC:
1909 case XFS_DA3_NODE_MAGIC:
1910 blk->magic = XFS_DA_NODE_MAGIC;
1911 node = (xfs_da_intnode_t *)info;
1912 dp->d_ops->node_hdr_from_disk(&nodehdr, node);
1913 btree = dp->d_ops->node_tree_p(node);
1914 blk->hashval = be32_to_cpu(btree[nodehdr.count - 1].hashval);
1915 if (forward)
1916 blk->index = 0;
1917 else
1918 blk->index = nodehdr.count - 1;
1919 blkno = be32_to_cpu(btree[blk->index].before);
1920 break;
1921 case XFS_ATTR_LEAF_MAGIC:
1922 case XFS_ATTR3_LEAF_MAGIC:
1923 blk->magic = XFS_ATTR_LEAF_MAGIC;
1924 ASSERT(level == path->active-1);
1925 blk->index = 0;
1926 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1927 break;
1928 case XFS_DIR2_LEAFN_MAGIC:
1929 case XFS_DIR3_LEAFN_MAGIC:
1930 blk->magic = XFS_DIR2_LEAFN_MAGIC;
1931 ASSERT(level == path->active-1);
1932 blk->index = 0;
1933 blk->hashval = xfs_dir2_leafn_lasthash(args->dp,
1934 blk->bp, NULL);
1935 break;
1936 default:
1937 ASSERT(0);
1938 break;
1939 }
1940 }
1941 *result = 0;
1942 return 0;
1943}
1944
1945
1946/*========================================================================
1947 * Utility routines.
1948 *========================================================================*/
1949
1950/*
1951 * Implement a simple hash on a character string.
1952 * Rotate the hash value by 7 bits, then XOR each character in.
1953 * This is implemented with some source-level loop unrolling.
1954 */
1955xfs_dahash_t
1956xfs_da_hashname(const __uint8_t *name, int namelen)
1957{
1958 xfs_dahash_t hash;
1959
1960 /*
1961 * Do four characters at a time as long as we can.
1962 */
1963 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1964 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1965 (name[3] << 0) ^ rol32(hash, 7 * 4);
1966
1967 /*
1968 * Now do the rest of the characters.
1969 */
1970 switch (namelen) {
1971 case 3:
1972 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1973 rol32(hash, 7 * 3);
1974 case 2:
1975 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1976 case 1:
1977 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1978 default: /* case 0: */
1979 return hash;
1980 }
1981}
1982
1983enum xfs_dacmp
1984xfs_da_compname(
1985 struct xfs_da_args *args,
1986 const unsigned char *name,
1987 int len)
1988{
1989 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1990 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1991}
1992
1993static xfs_dahash_t
1994xfs_default_hashname(
1995 struct xfs_name *name)
1996{
1997 return xfs_da_hashname(name->name, name->len);
1998}
1999
2000const struct xfs_nameops xfs_default_nameops = {
2001 .hashname = xfs_default_hashname,
2002 .compname = xfs_da_compname
2003};
2004
2005int
2006xfs_da_grow_inode_int(
2007 struct xfs_da_args *args,
2008 xfs_fileoff_t *bno,
2009 int count)
2010{
2011 struct xfs_trans *tp = args->trans;
2012 struct xfs_inode *dp = args->dp;
2013 int w = args->whichfork;
2014 xfs_rfsblock_t nblks = dp->i_d.di_nblocks;
2015 struct xfs_bmbt_irec map, *mapp;
2016 int nmap, error, got, i, mapi;
2017
2018 /*
2019 * Find a spot in the file space to put the new block.
2020 */
2021 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
2022 if (error)
2023 return error;
2024
2025 /*
2026 * Try mapping it in one filesystem block.
2027 */
2028 nmap = 1;
2029 ASSERT(args->firstblock != NULL);
2030 error = xfs_bmapi_write(tp, dp, *bno, count,
2031 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
2032 args->firstblock, args->total, &map, &nmap,
2033 args->flist);
2034 if (error)
2035 return error;
2036
2037 ASSERT(nmap <= 1);
2038 if (nmap == 1) {
2039 mapp = ↦
2040 mapi = 1;
2041 } else if (nmap == 0 && count > 1) {
2042 xfs_fileoff_t b;
2043 int c;
2044
2045 /*
2046 * If we didn't get it and the block might work if fragmented,
2047 * try without the CONTIG flag. Loop until we get it all.
2048 */
2049 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
2050 for (b = *bno, mapi = 0; b < *bno + count; ) {
2051 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
2052 c = (int)(*bno + count - b);
2053 error = xfs_bmapi_write(tp, dp, b, c,
2054 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
2055 args->firstblock, args->total,
2056 &mapp[mapi], &nmap, args->flist);
2057 if (error)
2058 goto out_free_map;
2059 if (nmap < 1)
2060 break;
2061 mapi += nmap;
2062 b = mapp[mapi - 1].br_startoff +
2063 mapp[mapi - 1].br_blockcount;
2064 }
2065 } else {
2066 mapi = 0;
2067 mapp = NULL;
2068 }
2069
2070 /*
2071 * Count the blocks we got, make sure it matches the total.
2072 */
2073 for (i = 0, got = 0; i < mapi; i++)
2074 got += mapp[i].br_blockcount;
2075 if (got != count || mapp[0].br_startoff != *bno ||
2076 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
2077 *bno + count) {
2078 error = -ENOSPC;
2079 goto out_free_map;
2080 }
2081
2082 /* account for newly allocated blocks in reserved blocks total */
2083 args->total -= dp->i_d.di_nblocks - nblks;
2084
2085out_free_map:
2086 if (mapp != &map)
2087 kmem_free(mapp);
2088 return error;
2089}
2090
2091/*
2092 * Add a block to the btree ahead of the file.
2093 * Return the new block number to the caller.
2094 */
2095int
2096xfs_da_grow_inode(
2097 struct xfs_da_args *args,
2098 xfs_dablk_t *new_blkno)
2099{
2100 xfs_fileoff_t bno;
2101 int error;
2102
2103 trace_xfs_da_grow_inode(args);
2104
2105 bno = args->geo->leafblk;
2106 error = xfs_da_grow_inode_int(args, &bno, args->geo->fsbcount);
2107 if (!error)
2108 *new_blkno = (xfs_dablk_t)bno;
2109 return error;
2110}
2111
2112/*
2113 * Ick. We need to always be able to remove a btree block, even
2114 * if there's no space reservation because the filesystem is full.
2115 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
2116 * It swaps the target block with the last block in the file. The
2117 * last block in the file can always be removed since it can't cause
2118 * a bmap btree split to do that.
2119 */
2120STATIC int
2121xfs_da3_swap_lastblock(
2122 struct xfs_da_args *args,
2123 xfs_dablk_t *dead_blknop,
2124 struct xfs_buf **dead_bufp)
2125{
2126 struct xfs_da_blkinfo *dead_info;
2127 struct xfs_da_blkinfo *sib_info;
2128 struct xfs_da_intnode *par_node;
2129 struct xfs_da_intnode *dead_node;
2130 struct xfs_dir2_leaf *dead_leaf2;
2131 struct xfs_da_node_entry *btree;
2132 struct xfs_da3_icnode_hdr par_hdr;
2133 struct xfs_inode *dp;
2134 struct xfs_trans *tp;
2135 struct xfs_mount *mp;
2136 struct xfs_buf *dead_buf;
2137 struct xfs_buf *last_buf;
2138 struct xfs_buf *sib_buf;
2139 struct xfs_buf *par_buf;
2140 xfs_dahash_t dead_hash;
2141 xfs_fileoff_t lastoff;
2142 xfs_dablk_t dead_blkno;
2143 xfs_dablk_t last_blkno;
2144 xfs_dablk_t sib_blkno;
2145 xfs_dablk_t par_blkno;
2146 int error;
2147 int w;
2148 int entno;
2149 int level;
2150 int dead_level;
2151
2152 trace_xfs_da_swap_lastblock(args);
2153
2154 dead_buf = *dead_bufp;
2155 dead_blkno = *dead_blknop;
2156 tp = args->trans;
2157 dp = args->dp;
2158 w = args->whichfork;
2159 ASSERT(w == XFS_DATA_FORK);
2160 mp = dp->i_mount;
2161 lastoff = args->geo->freeblk;
2162 error = xfs_bmap_last_before(tp, dp, &lastoff, w);
2163 if (error)
2164 return error;
2165 if (unlikely(lastoff == 0)) {
2166 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
2167 mp);
2168 return -EFSCORRUPTED;
2169 }
2170 /*
2171 * Read the last block in the btree space.
2172 */
2173 last_blkno = (xfs_dablk_t)lastoff - args->geo->fsbcount;
2174 error = xfs_da3_node_read(tp, dp, last_blkno, -1, &last_buf, w);
2175 if (error)
2176 return error;
2177 /*
2178 * Copy the last block into the dead buffer and log it.
2179 */
2180 memcpy(dead_buf->b_addr, last_buf->b_addr, args->geo->blksize);
2181 xfs_trans_log_buf(tp, dead_buf, 0, args->geo->blksize - 1);
2182 dead_info = dead_buf->b_addr;
2183 /*
2184 * Get values from the moved block.
2185 */
2186 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
2187 dead_info->magic == cpu_to_be16(XFS_DIR3_LEAFN_MAGIC)) {
2188 struct xfs_dir3_icleaf_hdr leafhdr;
2189 struct xfs_dir2_leaf_entry *ents;
2190
2191 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
2192 dp->d_ops->leaf_hdr_from_disk(&leafhdr, dead_leaf2);
2193 ents = dp->d_ops->leaf_ents_p(dead_leaf2);
2194 dead_level = 0;
2195 dead_hash = be32_to_cpu(ents[leafhdr.count - 1].hashval);
2196 } else {
2197 struct xfs_da3_icnode_hdr deadhdr;
2198
2199 dead_node = (xfs_da_intnode_t *)dead_info;
2200 dp->d_ops->node_hdr_from_disk(&deadhdr, dead_node);
2201 btree = dp->d_ops->node_tree_p(dead_node);
2202 dead_level = deadhdr.level;
2203 dead_hash = be32_to_cpu(btree[deadhdr.count - 1].hashval);
2204 }
2205 sib_buf = par_buf = NULL;
2206 /*
2207 * If the moved block has a left sibling, fix up the pointers.
2208 */
2209 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
2210 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2211 if (error)
2212 goto done;
2213 sib_info = sib_buf->b_addr;
2214 if (unlikely(
2215 be32_to_cpu(sib_info->forw) != last_blkno ||
2216 sib_info->magic != dead_info->magic)) {
2217 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
2218 XFS_ERRLEVEL_LOW, mp);
2219 error = -EFSCORRUPTED;
2220 goto done;
2221 }
2222 sib_info->forw = cpu_to_be32(dead_blkno);
2223 xfs_trans_log_buf(tp, sib_buf,
2224 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
2225 sizeof(sib_info->forw)));
2226 sib_buf = NULL;
2227 }
2228 /*
2229 * If the moved block has a right sibling, fix up the pointers.
2230 */
2231 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
2232 error = xfs_da3_node_read(tp, dp, sib_blkno, -1, &sib_buf, w);
2233 if (error)
2234 goto done;
2235 sib_info = sib_buf->b_addr;
2236 if (unlikely(
2237 be32_to_cpu(sib_info->back) != last_blkno ||
2238 sib_info->magic != dead_info->magic)) {
2239 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
2240 XFS_ERRLEVEL_LOW, mp);
2241 error = -EFSCORRUPTED;
2242 goto done;
2243 }
2244 sib_info->back = cpu_to_be32(dead_blkno);
2245 xfs_trans_log_buf(tp, sib_buf,
2246 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
2247 sizeof(sib_info->back)));
2248 sib_buf = NULL;
2249 }
2250 par_blkno = args->geo->leafblk;
2251 level = -1;
2252 /*
2253 * Walk down the tree looking for the parent of the moved block.
2254 */
2255 for (;;) {
2256 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2257 if (error)
2258 goto done;
2259 par_node = par_buf->b_addr;
2260 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2261 if (level >= 0 && level != par_hdr.level + 1) {
2262 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
2263 XFS_ERRLEVEL_LOW, mp);
2264 error = -EFSCORRUPTED;
2265 goto done;
2266 }
2267 level = par_hdr.level;
2268 btree = dp->d_ops->node_tree_p(par_node);
2269 for (entno = 0;
2270 entno < par_hdr.count &&
2271 be32_to_cpu(btree[entno].hashval) < dead_hash;
2272 entno++)
2273 continue;
2274 if (entno == par_hdr.count) {
2275 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
2276 XFS_ERRLEVEL_LOW, mp);
2277 error = -EFSCORRUPTED;
2278 goto done;
2279 }
2280 par_blkno = be32_to_cpu(btree[entno].before);
2281 if (level == dead_level + 1)
2282 break;
2283 xfs_trans_brelse(tp, par_buf);
2284 par_buf = NULL;
2285 }
2286 /*
2287 * We're in the right parent block.
2288 * Look for the right entry.
2289 */
2290 for (;;) {
2291 for (;
2292 entno < par_hdr.count &&
2293 be32_to_cpu(btree[entno].before) != last_blkno;
2294 entno++)
2295 continue;
2296 if (entno < par_hdr.count)
2297 break;
2298 par_blkno = par_hdr.forw;
2299 xfs_trans_brelse(tp, par_buf);
2300 par_buf = NULL;
2301 if (unlikely(par_blkno == 0)) {
2302 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
2303 XFS_ERRLEVEL_LOW, mp);
2304 error = -EFSCORRUPTED;
2305 goto done;
2306 }
2307 error = xfs_da3_node_read(tp, dp, par_blkno, -1, &par_buf, w);
2308 if (error)
2309 goto done;
2310 par_node = par_buf->b_addr;
2311 dp->d_ops->node_hdr_from_disk(&par_hdr, par_node);
2312 if (par_hdr.level != level) {
2313 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
2314 XFS_ERRLEVEL_LOW, mp);
2315 error = -EFSCORRUPTED;
2316 goto done;
2317 }
2318 btree = dp->d_ops->node_tree_p(par_node);
2319 entno = 0;
2320 }
2321 /*
2322 * Update the parent entry pointing to the moved block.
2323 */
2324 btree[entno].before = cpu_to_be32(dead_blkno);
2325 xfs_trans_log_buf(tp, par_buf,
2326 XFS_DA_LOGRANGE(par_node, &btree[entno].before,
2327 sizeof(btree[entno].before)));
2328 *dead_blknop = last_blkno;
2329 *dead_bufp = last_buf;
2330 return 0;
2331done:
2332 if (par_buf)
2333 xfs_trans_brelse(tp, par_buf);
2334 if (sib_buf)
2335 xfs_trans_brelse(tp, sib_buf);
2336 xfs_trans_brelse(tp, last_buf);
2337 return error;
2338}
2339
2340/*
2341 * Remove a btree block from a directory or attribute.
2342 */
2343int
2344xfs_da_shrink_inode(
2345 xfs_da_args_t *args,
2346 xfs_dablk_t dead_blkno,
2347 struct xfs_buf *dead_buf)
2348{
2349 xfs_inode_t *dp;
2350 int done, error, w, count;
2351 xfs_trans_t *tp;
2352
2353 trace_xfs_da_shrink_inode(args);
2354
2355 dp = args->dp;
2356 w = args->whichfork;
2357 tp = args->trans;
2358 count = args->geo->fsbcount;
2359 for (;;) {
2360 /*
2361 * Remove extents. If we get ENOSPC for a dir we have to move
2362 * the last block to the place we want to kill.
2363 */
2364 error = xfs_bunmapi(tp, dp, dead_blkno, count,
2365 xfs_bmapi_aflag(w), 0, args->firstblock,
2366 args->flist, &done);
2367 if (error == -ENOSPC) {
2368 if (w != XFS_DATA_FORK)
2369 break;
2370 error = xfs_da3_swap_lastblock(args, &dead_blkno,
2371 &dead_buf);
2372 if (error)
2373 break;
2374 } else {
2375 break;
2376 }
2377 }
2378 xfs_trans_binval(tp, dead_buf);
2379 return error;
2380}
2381
2382/*
2383 * See if the mapping(s) for this btree block are valid, i.e.
2384 * don't contain holes, are logically contiguous, and cover the whole range.
2385 */
2386STATIC int
2387xfs_da_map_covers_blocks(
2388 int nmap,
2389 xfs_bmbt_irec_t *mapp,
2390 xfs_dablk_t bno,
2391 int count)
2392{
2393 int i;
2394 xfs_fileoff_t off;
2395
2396 for (i = 0, off = bno; i < nmap; i++) {
2397 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2398 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2399 return 0;
2400 }
2401 if (off != mapp[i].br_startoff) {
2402 return 0;
2403 }
2404 off += mapp[i].br_blockcount;
2405 }
2406 return off == bno + count;
2407}
2408
2409/*
2410 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
2411 *
2412 * For the single map case, it is assumed that the caller has provided a pointer
2413 * to a valid xfs_buf_map. For the multiple map case, this function will
2414 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
2415 * map pointer with the allocated map.
2416 */
2417static int
2418xfs_buf_map_from_irec(
2419 struct xfs_mount *mp,
2420 struct xfs_buf_map **mapp,
2421 int *nmaps,
2422 struct xfs_bmbt_irec *irecs,
2423 int nirecs)
2424{
2425 struct xfs_buf_map *map;
2426 int i;
2427
2428 ASSERT(*nmaps == 1);
2429 ASSERT(nirecs >= 1);
2430
2431 if (nirecs > 1) {
2432 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map),
2433 KM_SLEEP | KM_NOFS);
2434 if (!map)
2435 return -ENOMEM;
2436 *mapp = map;
2437 }
2438
2439 *nmaps = nirecs;
2440 map = *mapp;
2441 for (i = 0; i < *nmaps; i++) {
2442 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
2443 irecs[i].br_startblock != HOLESTARTBLOCK);
2444 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
2445 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
2446 }
2447 return 0;
2448}
2449
2450/*
2451 * Map the block we are given ready for reading. There are three possible return
2452 * values:
2453 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
2454 * caller knows not to execute a subsequent read.
2455 * 0 - if we mapped the block successfully
2456 * >0 - positive error number if there was an error.
2457 */
2458static int
2459xfs_dabuf_map(
2460 struct xfs_inode *dp,
2461 xfs_dablk_t bno,
2462 xfs_daddr_t mappedbno,
2463 int whichfork,
2464 struct xfs_buf_map **map,
2465 int *nmaps)
2466{
2467 struct xfs_mount *mp = dp->i_mount;
2468 int nfsb;
2469 int error = 0;
2470 struct xfs_bmbt_irec irec;
2471 struct xfs_bmbt_irec *irecs = &irec;
2472 int nirecs;
2473
2474 ASSERT(map && *map);
2475 ASSERT(*nmaps == 1);
2476
2477 if (whichfork == XFS_DATA_FORK)
2478 nfsb = mp->m_dir_geo->fsbcount;
2479 else
2480 nfsb = mp->m_attr_geo->fsbcount;
2481
2482 /*
2483 * Caller doesn't have a mapping. -2 means don't complain
2484 * if we land in a hole.
2485 */
2486 if (mappedbno == -1 || mappedbno == -2) {
2487 /*
2488 * Optimize the one-block case.
2489 */
2490 if (nfsb != 1)
2491 irecs = kmem_zalloc(sizeof(irec) * nfsb,
2492 KM_SLEEP | KM_NOFS);
2493
2494 nirecs = nfsb;
2495 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2496 &nirecs, xfs_bmapi_aflag(whichfork));
2497 if (error)
2498 goto out;
2499 } else {
2500 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2501 irecs->br_startoff = (xfs_fileoff_t)bno;
2502 irecs->br_blockcount = nfsb;
2503 irecs->br_state = 0;
2504 nirecs = 1;
2505 }
2506
2507 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2508 error = mappedbno == -2 ? -1 : -EFSCORRUPTED;
2509 if (unlikely(error == -EFSCORRUPTED)) {
2510 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2511 int i;
2512 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2513 __func__, (long long)bno,
2514 (long long)dp->i_ino);
2515 for (i = 0; i < *nmaps; i++) {
2516 xfs_alert(mp,
2517"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2518 i,
2519 (long long)irecs[i].br_startoff,
2520 (long long)irecs[i].br_startblock,
2521 (long long)irecs[i].br_blockcount,
2522 irecs[i].br_state);
2523 }
2524 }
2525 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2526 XFS_ERRLEVEL_LOW, mp);
2527 }
2528 goto out;
2529 }
2530 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2531out:
2532 if (irecs != &irec)
2533 kmem_free(irecs);
2534 return error;
2535}
2536
2537/*
2538 * Get a buffer for the dir/attr block.
2539 */
2540int
2541xfs_da_get_buf(
2542 struct xfs_trans *trans,
2543 struct xfs_inode *dp,
2544 xfs_dablk_t bno,
2545 xfs_daddr_t mappedbno,
2546 struct xfs_buf **bpp,
2547 int whichfork)
2548{
2549 struct xfs_buf *bp;
2550 struct xfs_buf_map map;
2551 struct xfs_buf_map *mapp;
2552 int nmap;
2553 int error;
2554
2555 *bpp = NULL;
2556 mapp = ↦
2557 nmap = 1;
2558 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2559 &mapp, &nmap);
2560 if (error) {
2561 /* mapping a hole is not an error, but we don't continue */
2562 if (error == -1)
2563 error = 0;
2564 goto out_free;
2565 }
2566
2567 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2568 mapp, nmap, 0);
2569 error = bp ? bp->b_error : -EIO;
2570 if (error) {
2571 if (bp)
2572 xfs_trans_brelse(trans, bp);
2573 goto out_free;
2574 }
2575
2576 *bpp = bp;
2577
2578out_free:
2579 if (mapp != &map)
2580 kmem_free(mapp);
2581
2582 return error;
2583}
2584
2585/*
2586 * Get a buffer for the dir/attr block, fill in the contents.
2587 */
2588int
2589xfs_da_read_buf(
2590 struct xfs_trans *trans,
2591 struct xfs_inode *dp,
2592 xfs_dablk_t bno,
2593 xfs_daddr_t mappedbno,
2594 struct xfs_buf **bpp,
2595 int whichfork,
2596 const struct xfs_buf_ops *ops)
2597{
2598 struct xfs_buf *bp;
2599 struct xfs_buf_map map;
2600 struct xfs_buf_map *mapp;
2601 int nmap;
2602 int error;
2603
2604 *bpp = NULL;
2605 mapp = ↦
2606 nmap = 1;
2607 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2608 &mapp, &nmap);
2609 if (error) {
2610 /* mapping a hole is not an error, but we don't continue */
2611 if (error == -1)
2612 error = 0;
2613 goto out_free;
2614 }
2615
2616 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2617 dp->i_mount->m_ddev_targp,
2618 mapp, nmap, 0, &bp, ops);
2619 if (error)
2620 goto out_free;
2621
2622 if (whichfork == XFS_ATTR_FORK)
2623 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2624 else
2625 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2626 *bpp = bp;
2627out_free:
2628 if (mapp != &map)
2629 kmem_free(mapp);
2630
2631 return error;
2632}
2633
2634/*
2635 * Readahead the dir/attr block.
2636 */
2637xfs_daddr_t
2638xfs_da_reada_buf(
2639 struct xfs_inode *dp,
2640 xfs_dablk_t bno,
2641 xfs_daddr_t mappedbno,
2642 int whichfork,
2643 const struct xfs_buf_ops *ops)
2644{
2645 struct xfs_buf_map map;
2646 struct xfs_buf_map *mapp;
2647 int nmap;
2648 int error;
2649
2650 mapp = ↦
2651 nmap = 1;
2652 error = xfs_dabuf_map(dp, bno, mappedbno, whichfork,
2653 &mapp, &nmap);
2654 if (error) {
2655 /* mapping a hole is not an error, but we don't continue */
2656 if (error == -1)
2657 error = 0;
2658 goto out_free;
2659 }
2660
2661 mappedbno = mapp[0].bm_bn;
2662 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
2663
2664out_free:
2665 if (mapp != &map)
2666 kmem_free(mapp);
2667
2668 if (error)
2669 return -1;
2670 return mappedbno;
2671}