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[PATCH] USB: new devices for the Option driver
[usb.git] / fs / xfs / xfs_da_btree.c
blob8988b9051175f98e14bb96eaa0d49630a5e473fe
1 /*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_dir.h"
28 #include "xfs_dir2.h"
29 #include "xfs_dmapi.h"
30 #include "xfs_mount.h"
31 #include "xfs_da_btree.h"
32 #include "xfs_bmap_btree.h"
33 #include "xfs_alloc_btree.h"
34 #include "xfs_ialloc_btree.h"
35 #include "xfs_dir_sf.h"
36 #include "xfs_dir2_sf.h"
37 #include "xfs_attr_sf.h"
38 #include "xfs_dinode.h"
39 #include "xfs_inode.h"
40 #include "xfs_inode_item.h"
41 #include "xfs_alloc.h"
42 #include "xfs_btree.h"
43 #include "xfs_bmap.h"
44 #include "xfs_attr.h"
45 #include "xfs_attr_leaf.h"
46 #include "xfs_dir_leaf.h"
47 #include "xfs_dir2_data.h"
48 #include "xfs_dir2_leaf.h"
49 #include "xfs_dir2_block.h"
50 #include "xfs_dir2_node.h"
51 #include "xfs_error.h"
52
53 /*
54 * xfs_da_btree.c
55 *
56 * Routines to implement directories as Btrees of hashed names.
57 */
58
59 /*========================================================================
60 * Function prototypes for the kernel.
61 *========================================================================*/
62
63 /*
64 * Routines used for growing the Btree.
65 */
66 STATIC int xfs_da_root_split(xfs_da_state_t *state,
67 xfs_da_state_blk_t *existing_root,
68 xfs_da_state_blk_t *new_child);
69 STATIC int xfs_da_node_split(xfs_da_state_t *state,
70 xfs_da_state_blk_t *existing_blk,
71 xfs_da_state_blk_t *split_blk,
72 xfs_da_state_blk_t *blk_to_add,
73 int treelevel,
74 int *result);
75 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
76 xfs_da_state_blk_t *node_blk_1,
77 xfs_da_state_blk_t *node_blk_2);
78 STATIC void xfs_da_node_add(xfs_da_state_t *state,
79 xfs_da_state_blk_t *old_node_blk,
80 xfs_da_state_blk_t *new_node_blk);
81
82 /*
83 * Routines used for shrinking the Btree.
84 */
85 STATIC int xfs_da_root_join(xfs_da_state_t *state,
86 xfs_da_state_blk_t *root_blk);
87 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
88 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
89 xfs_da_state_blk_t *drop_blk);
90 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
91 xfs_da_state_blk_t *src_node_blk,
92 xfs_da_state_blk_t *dst_node_blk);
93
94 /*
95 * Utility routines.
96 */
97 STATIC uint xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count);
98 STATIC int xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp);
99 STATIC xfs_dabuf_t *xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra);
100 STATIC int xfs_da_blk_unlink(xfs_da_state_t *state,
101 xfs_da_state_blk_t *drop_blk,
102 xfs_da_state_blk_t *save_blk);
103 STATIC void xfs_da_state_kill_altpath(xfs_da_state_t *state);
104
105 /*========================================================================
106 * Routines used for growing the Btree.
107 *========================================================================*/
108
109 /*
110 * Create the initial contents of an intermediate node.
111 */
112 int
113 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
114 xfs_dabuf_t **bpp, int whichfork)
115 {
116 xfs_da_intnode_t *node;
117 xfs_dabuf_t *bp;
118 int error;
119 xfs_trans_t *tp;
120
121 tp = args->trans;
122 error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
123 if (error)
124 return(error);
125 ASSERT(bp != NULL);
126 node = bp->data;
127 node->hdr.info.forw = 0;
128 node->hdr.info.back = 0;
129 node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
130 node->hdr.info.pad = 0;
131 node->hdr.count = 0;
132 node->hdr.level = cpu_to_be16(level);
133
134 xfs_da_log_buf(tp, bp,
135 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
136
137 *bpp = bp;
138 return(0);
139 }
140
141 /*
142 * Split a leaf node, rebalance, then possibly split
143 * intermediate nodes, rebalance, etc.
144 */
145 int /* error */
146 xfs_da_split(xfs_da_state_t *state)
147 {
148 xfs_da_state_blk_t *oldblk, *newblk, *addblk;
149 xfs_da_intnode_t *node;
150 xfs_dabuf_t *bp;
151 int max, action, error, i;
152
153 /*
154 * Walk back up the tree splitting/inserting/adjusting as necessary.
155 * If we need to insert and there isn't room, split the node, then
156 * decide which fragment to insert the new block from below into.
157 * Note that we may split the root this way, but we need more fixup.
158 */
159 max = state->path.active - 1;
160 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
161 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
162 state->path.blk[max].magic == XFS_DIRX_LEAF_MAGIC(state->mp));
163
164 addblk = &state->path.blk[max]; /* initial dummy value */
165 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
166 oldblk = &state->path.blk[i];
167 newblk = &state->altpath.blk[i];
168
169 /*
170 * If a leaf node then
171 * Allocate a new leaf node, then rebalance across them.
172 * else if an intermediate node then
173 * We split on the last layer, must we split the node?
174 */
175 switch (oldblk->magic) {
176 case XFS_ATTR_LEAF_MAGIC:
177 error = xfs_attr_leaf_split(state, oldblk, newblk);
178 if ((error != 0) && (error != ENOSPC)) {
179 return(error); /* GROT: attr is inconsistent */
180 }
181 if (!error) {
182 addblk = newblk;
183 break;
184 }
185 /*
186 * Entry wouldn't fit, split the leaf again.
187 */
188 state->extravalid = 1;
189 if (state->inleaf) {
190 state->extraafter = 0; /* before newblk */
191 error = xfs_attr_leaf_split(state, oldblk,
192 &state->extrablk);
193 } else {
194 state->extraafter = 1; /* after newblk */
195 error = xfs_attr_leaf_split(state, newblk,
196 &state->extrablk);
197 }
198 if (error)
199 return(error); /* GROT: attr inconsistent */
200 addblk = newblk;
201 break;
202 case XFS_DIR_LEAF_MAGIC:
203 ASSERT(XFS_DIR_IS_V1(state->mp));
204 error = xfs_dir_leaf_split(state, oldblk, newblk);
205 if ((error != 0) && (error != ENOSPC)) {
206 return(error); /* GROT: dir is inconsistent */
207 }
208 if (!error) {
209 addblk = newblk;
210 break;
211 }
212 /*
213 * Entry wouldn't fit, split the leaf again.
214 */
215 state->extravalid = 1;
216 if (state->inleaf) {
217 state->extraafter = 0; /* before newblk */
218 error = xfs_dir_leaf_split(state, oldblk,
219 &state->extrablk);
220 if (error)
221 return(error); /* GROT: dir incon. */
222 addblk = newblk;
223 } else {
224 state->extraafter = 1; /* after newblk */
225 error = xfs_dir_leaf_split(state, newblk,
226 &state->extrablk);
227 if (error)
228 return(error); /* GROT: dir incon. */
229 addblk = newblk;
230 }
231 break;
232 case XFS_DIR2_LEAFN_MAGIC:
233 ASSERT(XFS_DIR_IS_V2(state->mp));
234 error = xfs_dir2_leafn_split(state, oldblk, newblk);
235 if (error)
236 return error;
237 addblk = newblk;
238 break;
239 case XFS_DA_NODE_MAGIC:
240 error = xfs_da_node_split(state, oldblk, newblk, addblk,
241 max - i, &action);
242 xfs_da_buf_done(addblk->bp);
243 addblk->bp = NULL;
244 if (error)
245 return(error); /* GROT: dir is inconsistent */
246 /*
247 * Record the newly split block for the next time thru?
248 */
249 if (action)
250 addblk = newblk;
251 else
252 addblk = NULL;
253 break;
254 }
255
256 /*
257 * Update the btree to show the new hashval for this child.
258 */
259 xfs_da_fixhashpath(state, &state->path);
260 /*
261 * If we won't need this block again, it's getting dropped
262 * from the active path by the loop control, so we need
263 * to mark it done now.
264 */
265 if (i > 0 || !addblk)
266 xfs_da_buf_done(oldblk->bp);
267 }
268 if (!addblk)
269 return(0);
270
271 /*
272 * Split the root node.
273 */
274 ASSERT(state->path.active == 0);
275 oldblk = &state->path.blk[0];
276 error = xfs_da_root_split(state, oldblk, addblk);
277 if (error) {
278 xfs_da_buf_done(oldblk->bp);
279 xfs_da_buf_done(addblk->bp);
280 addblk->bp = NULL;
281 return(error); /* GROT: dir is inconsistent */
282 }
283
284 /*
285 * Update pointers to the node which used to be block 0 and
286 * just got bumped because of the addition of a new root node.
287 * There might be three blocks involved if a double split occurred,
288 * and the original block 0 could be at any position in the list.
289 */
290
291 node = oldblk->bp->data;
292 if (node->hdr.info.forw) {
293 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
294 bp = addblk->bp;
295 } else {
296 ASSERT(state->extravalid);
297 bp = state->extrablk.bp;
298 }
299 node = bp->data;
300 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
301 xfs_da_log_buf(state->args->trans, bp,
302 XFS_DA_LOGRANGE(node, &node->hdr.info,
303 sizeof(node->hdr.info)));
304 }
305 node = oldblk->bp->data;
306 if (node->hdr.info.back) {
307 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
308 bp = addblk->bp;
309 } else {
310 ASSERT(state->extravalid);
311 bp = state->extrablk.bp;
312 }
313 node = bp->data;
314 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
315 xfs_da_log_buf(state->args->trans, bp,
316 XFS_DA_LOGRANGE(node, &node->hdr.info,
317 sizeof(node->hdr.info)));
318 }
319 xfs_da_buf_done(oldblk->bp);
320 xfs_da_buf_done(addblk->bp);
321 addblk->bp = NULL;
322 return(0);
323 }
324
325 /*
326 * Split the root. We have to create a new root and point to the two
327 * parts (the split old root) that we just created. Copy block zero to
328 * the EOF, extending the inode in process.
329 */
330 STATIC int /* error */
331 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
332 xfs_da_state_blk_t *blk2)
333 {
334 xfs_da_intnode_t *node, *oldroot;
335 xfs_da_args_t *args;
336 xfs_dablk_t blkno;
337 xfs_dabuf_t *bp;
338 int error, size;
339 xfs_inode_t *dp;
340 xfs_trans_t *tp;
341 xfs_mount_t *mp;
342 xfs_dir2_leaf_t *leaf;
343
344 /*
345 * Copy the existing (incorrect) block from the root node position
346 * to a free space somewhere.
347 */
348 args = state->args;
349 ASSERT(args != NULL);
350 error = xfs_da_grow_inode(args, &blkno);
351 if (error)
352 return(error);
353 dp = args->dp;
354 tp = args->trans;
355 mp = state->mp;
356 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
357 if (error)
358 return(error);
359 ASSERT(bp != NULL);
360 node = bp->data;
361 oldroot = blk1->bp->data;
362 if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC) {
363 size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
364 (char *)oldroot);
365 } else {
366 ASSERT(XFS_DIR_IS_V2(mp));
367 ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC);
368 leaf = (xfs_dir2_leaf_t *)oldroot;
369 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
370 (char *)leaf);
371 }
372 memcpy(node, oldroot, size);
373 xfs_da_log_buf(tp, bp, 0, size - 1);
374 xfs_da_buf_done(blk1->bp);
375 blk1->bp = bp;
376 blk1->blkno = blkno;
377
378 /*
379 * Set up the new root node.
380 */
381 error = xfs_da_node_create(args,
382 args->whichfork == XFS_DATA_FORK &&
383 XFS_DIR_IS_V2(mp) ? mp->m_dirleafblk : 0,
384 be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
385 if (error)
386 return(error);
387 node = bp->data;
388 node->btree[0].hashval = cpu_to_be32(blk1->hashval);
389 node->btree[0].before = cpu_to_be32(blk1->blkno);
390 node->btree[1].hashval = cpu_to_be32(blk2->hashval);
391 node->btree[1].before = cpu_to_be32(blk2->blkno);
392 node->hdr.count = cpu_to_be16(2);
393
394 #ifdef DEBUG
395 if (be16_to_cpu(oldroot->hdr.info.magic) == XFS_DIR2_LEAFN_MAGIC) {
396 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
397 blk1->blkno < mp->m_dirfreeblk);
398 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
399 blk2->blkno < mp->m_dirfreeblk);
400 }
401 #endif
402
403 /* Header is already logged by xfs_da_node_create */
404 xfs_da_log_buf(tp, bp,
405 XFS_DA_LOGRANGE(node, node->btree,
406 sizeof(xfs_da_node_entry_t) * 2));
407 xfs_da_buf_done(bp);
408
409 return(0);
410 }
411
412 /*
413 * Split the node, rebalance, then add the new entry.
414 */
415 STATIC int /* error */
416 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
417 xfs_da_state_blk_t *newblk,
418 xfs_da_state_blk_t *addblk,
419 int treelevel, int *result)
420 {
421 xfs_da_intnode_t *node;
422 xfs_dablk_t blkno;
423 int newcount, error;
424 int useextra;
425
426 node = oldblk->bp->data;
427 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
428
429 /*
430 * With V2 the extra block is data or freespace.
431 */
432 useextra = state->extravalid && (XFS_DIR_IS_V1(state->mp) ||
433 state->args->whichfork == XFS_ATTR_FORK);
434 newcount = 1 + useextra;
435 /*
436 * Do we have to split the node?
437 */
438 if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
439 /*
440 * Allocate a new node, add to the doubly linked chain of
441 * nodes, then move some of our excess entries into it.
442 */
443 error = xfs_da_grow_inode(state->args, &blkno);
444 if (error)
445 return(error); /* GROT: dir is inconsistent */
446
447 error = xfs_da_node_create(state->args, blkno, treelevel,
448 &newblk->bp, state->args->whichfork);
449 if (error)
450 return(error); /* GROT: dir is inconsistent */
451 newblk->blkno = blkno;
452 newblk->magic = XFS_DA_NODE_MAGIC;
453 xfs_da_node_rebalance(state, oldblk, newblk);
454 error = xfs_da_blk_link(state, oldblk, newblk);
455 if (error)
456 return(error);
457 *result = 1;
458 } else {
459 *result = 0;
460 }
461
462 /*
463 * Insert the new entry(s) into the correct block
464 * (updating last hashval in the process).
465 *
466 * xfs_da_node_add() inserts BEFORE the given index,
467 * and as a result of using node_lookup_int() we always
468 * point to a valid entry (not after one), but a split
469 * operation always results in a new block whose hashvals
470 * FOLLOW the current block.
471 *
472 * If we had double-split op below us, then add the extra block too.
473 */
474 node = oldblk->bp->data;
475 if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
476 oldblk->index++;
477 xfs_da_node_add(state, oldblk, addblk);
478 if (useextra) {
479 if (state->extraafter)
480 oldblk->index++;
481 xfs_da_node_add(state, oldblk, &state->extrablk);
482 state->extravalid = 0;
483 }
484 } else {
485 newblk->index++;
486 xfs_da_node_add(state, newblk, addblk);
487 if (useextra) {
488 if (state->extraafter)
489 newblk->index++;
490 xfs_da_node_add(state, newblk, &state->extrablk);
491 state->extravalid = 0;
492 }
493 }
494
495 return(0);
496 }
497
498 /*
499 * Balance the btree elements between two intermediate nodes,
500 * usually one full and one empty.
501 *
502 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
503 */
504 STATIC void
505 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
506 xfs_da_state_blk_t *blk2)
507 {
508 xfs_da_intnode_t *node1, *node2, *tmpnode;
509 xfs_da_node_entry_t *btree_s, *btree_d;
510 int count, tmp;
511 xfs_trans_t *tp;
512
513 node1 = blk1->bp->data;
514 node2 = blk2->bp->data;
515 /*
516 * Figure out how many entries need to move, and in which direction.
517 * Swap the nodes around if that makes it simpler.
518 */
519 if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
520 ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
521 (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
522 be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
523 tmpnode = node1;
524 node1 = node2;
525 node2 = tmpnode;
526 }
527 ASSERT(be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC);
528 ASSERT(be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC);
529 count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
530 if (count == 0)
531 return;
532 tp = state->args->trans;
533 /*
534 * Two cases: high-to-low and low-to-high.
535 */
536 if (count > 0) {
537 /*
538 * Move elements in node2 up to make a hole.
539 */
540 if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
541 tmp *= (uint)sizeof(xfs_da_node_entry_t);
542 btree_s = &node2->btree[0];
543 btree_d = &node2->btree[count];
544 memmove(btree_d, btree_s, tmp);
545 }
546
547 /*
548 * Move the req'd B-tree elements from high in node1 to
549 * low in node2.
550 */
551 be16_add(&node2->hdr.count, count);
552 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
553 btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
554 btree_d = &node2->btree[0];
555 memcpy(btree_d, btree_s, tmp);
556 be16_add(&node1->hdr.count, -count);
557 } else {
558 /*
559 * Move the req'd B-tree elements from low in node2 to
560 * high in node1.
561 */
562 count = -count;
563 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
564 btree_s = &node2->btree[0];
565 btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
566 memcpy(btree_d, btree_s, tmp);
567 be16_add(&node1->hdr.count, count);
568 xfs_da_log_buf(tp, blk1->bp,
569 XFS_DA_LOGRANGE(node1, btree_d, tmp));
570
571 /*
572 * Move elements in node2 down to fill the hole.
573 */
574 tmp = be16_to_cpu(node2->hdr.count) - count;
575 tmp *= (uint)sizeof(xfs_da_node_entry_t);
576 btree_s = &node2->btree[count];
577 btree_d = &node2->btree[0];
578 memmove(btree_d, btree_s, tmp);
579 be16_add(&node2->hdr.count, -count);
580 }
581
582 /*
583 * Log header of node 1 and all current bits of node 2.
584 */
585 xfs_da_log_buf(tp, blk1->bp,
586 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
587 xfs_da_log_buf(tp, blk2->bp,
588 XFS_DA_LOGRANGE(node2, &node2->hdr,
589 sizeof(node2->hdr) +
590 sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
591
592 /*
593 * Record the last hashval from each block for upward propagation.
594 * (note: don't use the swapped node pointers)
595 */
596 node1 = blk1->bp->data;
597 node2 = blk2->bp->data;
598 blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
599 blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
600
601 /*
602 * Adjust the expected index for insertion.
603 */
604 if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
605 blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
606 blk1->index = be16_to_cpu(node1->hdr.count) + 1; /* make it invalid */
607 }
608 }
609
610 /*
611 * Add a new entry to an intermediate node.
612 */
613 STATIC void
614 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
615 xfs_da_state_blk_t *newblk)
616 {
617 xfs_da_intnode_t *node;
618 xfs_da_node_entry_t *btree;
619 int tmp;
620 xfs_mount_t *mp;
621
622 node = oldblk->bp->data;
623 mp = state->mp;
624 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
625 ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
626 ASSERT(newblk->blkno != 0);
627 if (state->args->whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
628 ASSERT(newblk->blkno >= mp->m_dirleafblk &&
629 newblk->blkno < mp->m_dirfreeblk);
630
631 /*
632 * We may need to make some room before we insert the new node.
633 */
634 tmp = 0;
635 btree = &node->btree[ oldblk->index ];
636 if (oldblk->index < be16_to_cpu(node->hdr.count)) {
637 tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
638 memmove(btree + 1, btree, tmp);
639 }
640 btree->hashval = cpu_to_be32(newblk->hashval);
641 btree->before = cpu_to_be32(newblk->blkno);
642 xfs_da_log_buf(state->args->trans, oldblk->bp,
643 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
644 be16_add(&node->hdr.count, 1);
645 xfs_da_log_buf(state->args->trans, oldblk->bp,
646 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
647
648 /*
649 * Copy the last hash value from the oldblk to propagate upwards.
650 */
651 oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
652 }
653
654 /*========================================================================
655 * Routines used for shrinking the Btree.
656 *========================================================================*/
657
658 /*
659 * Deallocate an empty leaf node, remove it from its parent,
660 * possibly deallocating that block, etc...
661 */
662 int
663 xfs_da_join(xfs_da_state_t *state)
664 {
665 xfs_da_state_blk_t *drop_blk, *save_blk;
666 int action, error;
667
668 action = 0;
669 drop_blk = &state->path.blk[ state->path.active-1 ];
670 save_blk = &state->altpath.blk[ state->path.active-1 ];
671 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
672 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
673 drop_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp));
674
675 /*
676 * Walk back up the tree joining/deallocating as necessary.
677 * When we stop dropping blocks, break out.
678 */
679 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
680 state->path.active--) {
681 /*
682 * See if we can combine the block with a neighbor.
683 * (action == 0) => no options, just leave
684 * (action == 1) => coalesce, then unlink
685 * (action == 2) => block empty, unlink it
686 */
687 switch (drop_blk->magic) {
688 case XFS_ATTR_LEAF_MAGIC:
689 error = xfs_attr_leaf_toosmall(state, &action);
690 if (error)
691 return(error);
692 if (action == 0)
693 return(0);
694 xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
695 break;
696 case XFS_DIR_LEAF_MAGIC:
697 ASSERT(XFS_DIR_IS_V1(state->mp));
698 error = xfs_dir_leaf_toosmall(state, &action);
699 if (error)
700 return(error);
701 if (action == 0)
702 return(0);
703 xfs_dir_leaf_unbalance(state, drop_blk, save_blk);
704 break;
705 case XFS_DIR2_LEAFN_MAGIC:
706 ASSERT(XFS_DIR_IS_V2(state->mp));
707 error = xfs_dir2_leafn_toosmall(state, &action);
708 if (error)
709 return error;
710 if (action == 0)
711 return 0;
712 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
713 break;
714 case XFS_DA_NODE_MAGIC:
715 /*
716 * Remove the offending node, fixup hashvals,
717 * check for a toosmall neighbor.
718 */
719 xfs_da_node_remove(state, drop_blk);
720 xfs_da_fixhashpath(state, &state->path);
721 error = xfs_da_node_toosmall(state, &action);
722 if (error)
723 return(error);
724 if (action == 0)
725 return 0;
726 xfs_da_node_unbalance(state, drop_blk, save_blk);
727 break;
728 }
729 xfs_da_fixhashpath(state, &state->altpath);
730 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
731 xfs_da_state_kill_altpath(state);
732 if (error)
733 return(error);
734 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
735 drop_blk->bp);
736 drop_blk->bp = NULL;
737 if (error)
738 return(error);
739 }
740 /*
741 * We joined all the way to the top. If it turns out that
742 * we only have one entry in the root, make the child block
743 * the new root.
744 */
745 xfs_da_node_remove(state, drop_blk);
746 xfs_da_fixhashpath(state, &state->path);
747 error = xfs_da_root_join(state, &state->path.blk[0]);
748 return(error);
749 }
750
751 /*
752 * We have only one entry in the root. Copy the only remaining child of
753 * the old root to block 0 as the new root node.
754 */
755 STATIC int
756 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
757 {
758 xfs_da_intnode_t *oldroot;
759 /* REFERENCED */
760 xfs_da_blkinfo_t *blkinfo;
761 xfs_da_args_t *args;
762 xfs_dablk_t child;
763 xfs_dabuf_t *bp;
764 int error;
765
766 args = state->args;
767 ASSERT(args != NULL);
768 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
769 oldroot = root_blk->bp->data;
770 ASSERT(be16_to_cpu(oldroot->hdr.info.magic) == XFS_DA_NODE_MAGIC);
771 ASSERT(!oldroot->hdr.info.forw);
772 ASSERT(!oldroot->hdr.info.back);
773
774 /*
775 * If the root has more than one child, then don't do anything.
776 */
777 if (be16_to_cpu(oldroot->hdr.count) > 1)
778 return(0);
779
780 /*
781 * Read in the (only) child block, then copy those bytes into
782 * the root block's buffer and free the original child block.
783 */
784 child = be32_to_cpu(oldroot->btree[0].before);
785 ASSERT(child != 0);
786 error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
787 args->whichfork);
788 if (error)
789 return(error);
790 ASSERT(bp != NULL);
791 blkinfo = bp->data;
792 if (be16_to_cpu(oldroot->hdr.level) == 1) {
793 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
794 be16_to_cpu(blkinfo->magic) == XFS_ATTR_LEAF_MAGIC);
795 } else {
796 ASSERT(be16_to_cpu(blkinfo->magic) == XFS_DA_NODE_MAGIC);
797 }
798 ASSERT(!blkinfo->forw);
799 ASSERT(!blkinfo->back);
800 memcpy(root_blk->bp->data, bp->data, state->blocksize);
801 xfs_da_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
802 error = xfs_da_shrink_inode(args, child, bp);
803 return(error);
804 }
805
806 /*
807 * Check a node block and its neighbors to see if the block should be
808 * collapsed into one or the other neighbor. Always keep the block
809 * with the smaller block number.
810 * If the current block is over 50% full, don't try to join it, return 0.
811 * If the block is empty, fill in the state structure and return 2.
812 * If it can be collapsed, fill in the state structure and return 1.
813 * If nothing can be done, return 0.
814 */
815 STATIC int
816 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
817 {
818 xfs_da_intnode_t *node;
819 xfs_da_state_blk_t *blk;
820 xfs_da_blkinfo_t *info;
821 int count, forward, error, retval, i;
822 xfs_dablk_t blkno;
823 xfs_dabuf_t *bp;
824
825 /*
826 * Check for the degenerate case of the block being over 50% full.
827 * If so, it's not worth even looking to see if we might be able
828 * to coalesce with a sibling.
829 */
830 blk = &state->path.blk[ state->path.active-1 ];
831 info = blk->bp->data;
832 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC);
833 node = (xfs_da_intnode_t *)info;
834 count = be16_to_cpu(node->hdr.count);
835 if (count > (state->node_ents >> 1)) {
836 *action = 0; /* blk over 50%, don't try to join */
837 return(0); /* blk over 50%, don't try to join */
838 }
839
840 /*
841 * Check for the degenerate case of the block being empty.
842 * If the block is empty, we'll simply delete it, no need to
843 * coalesce it with a sibling block. We choose (arbitrarily)
844 * to merge with the forward block unless it is NULL.
845 */
846 if (count == 0) {
847 /*
848 * Make altpath point to the block we want to keep and
849 * path point to the block we want to drop (this one).
850 */
851 forward = (info->forw != 0);
852 memcpy(&state->altpath, &state->path, sizeof(state->path));
853 error = xfs_da_path_shift(state, &state->altpath, forward,
854 0, &retval);
855 if (error)
856 return(error);
857 if (retval) {
858 *action = 0;
859 } else {
860 *action = 2;
861 }
862 return(0);
863 }
864
865 /*
866 * Examine each sibling block to see if we can coalesce with
867 * at least 25% free space to spare. We need to figure out
868 * whether to merge with the forward or the backward block.
869 * We prefer coalescing with the lower numbered sibling so as
870 * to shrink a directory over time.
871 */
872 /* start with smaller blk num */
873 forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
874 for (i = 0; i < 2; forward = !forward, i++) {
875 if (forward)
876 blkno = be32_to_cpu(info->forw);
877 else
878 blkno = be32_to_cpu(info->back);
879 if (blkno == 0)
880 continue;
881 error = xfs_da_read_buf(state->args->trans, state->args->dp,
882 blkno, -1, &bp, state->args->whichfork);
883 if (error)
884 return(error);
885 ASSERT(bp != NULL);
886
887 node = (xfs_da_intnode_t *)info;
888 count = state->node_ents;
889 count -= state->node_ents >> 2;
890 count -= be16_to_cpu(node->hdr.count);
891 node = bp->data;
892 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
893 count -= be16_to_cpu(node->hdr.count);
894 xfs_da_brelse(state->args->trans, bp);
895 if (count >= 0)
896 break; /* fits with at least 25% to spare */
897 }
898 if (i >= 2) {
899 *action = 0;
900 return(0);
901 }
902
903 /*
904 * Make altpath point to the block we want to keep (the lower
905 * numbered block) and path point to the block we want to drop.
906 */
907 memcpy(&state->altpath, &state->path, sizeof(state->path));
908 if (blkno < blk->blkno) {
909 error = xfs_da_path_shift(state, &state->altpath, forward,
910 0, &retval);
911 if (error) {
912 return(error);
913 }
914 if (retval) {
915 *action = 0;
916 return(0);
917 }
918 } else {
919 error = xfs_da_path_shift(state, &state->path, forward,
920 0, &retval);
921 if (error) {
922 return(error);
923 }
924 if (retval) {
925 *action = 0;
926 return(0);
927 }
928 }
929 *action = 1;
930 return(0);
931 }
932
933 /*
934 * Walk back up the tree adjusting hash values as necessary,
935 * when we stop making changes, return.
936 */
937 void
938 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
939 {
940 xfs_da_state_blk_t *blk;
941 xfs_da_intnode_t *node;
942 xfs_da_node_entry_t *btree;
943 xfs_dahash_t lasthash=0;
944 int level, count;
945
946 level = path->active-1;
947 blk = &path->blk[ level ];
948 switch (blk->magic) {
949 case XFS_ATTR_LEAF_MAGIC:
950 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
951 if (count == 0)
952 return;
953 break;
954 case XFS_DIR_LEAF_MAGIC:
955 ASSERT(XFS_DIR_IS_V1(state->mp));
956 lasthash = xfs_dir_leaf_lasthash(blk->bp, &count);
957 if (count == 0)
958 return;
959 break;
960 case XFS_DIR2_LEAFN_MAGIC:
961 ASSERT(XFS_DIR_IS_V2(state->mp));
962 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
963 if (count == 0)
964 return;
965 break;
966 case XFS_DA_NODE_MAGIC:
967 lasthash = xfs_da_node_lasthash(blk->bp, &count);
968 if (count == 0)
969 return;
970 break;
971 }
972 for (blk--, level--; level >= 0; blk--, level--) {
973 node = blk->bp->data;
974 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
975 btree = &node->btree[ blk->index ];
976 if (be32_to_cpu(btree->hashval) == lasthash)
977 break;
978 blk->hashval = lasthash;
979 btree->hashval = cpu_to_be32(lasthash);
980 xfs_da_log_buf(state->args->trans, blk->bp,
981 XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
982
983 lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
984 }
985 }
986
987 /*
988 * Remove an entry from an intermediate node.
989 */
990 STATIC void
991 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
992 {
993 xfs_da_intnode_t *node;
994 xfs_da_node_entry_t *btree;
995 int tmp;
996
997 node = drop_blk->bp->data;
998 ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
999 ASSERT(drop_blk->index >= 0);
1000
1001 /*
1002 * Copy over the offending entry, or just zero it out.
1003 */
1004 btree = &node->btree[drop_blk->index];
1005 if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
1006 tmp = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
1007 tmp *= (uint)sizeof(xfs_da_node_entry_t);
1008 memmove(btree, btree + 1, tmp);
1009 xfs_da_log_buf(state->args->trans, drop_blk->bp,
1010 XFS_DA_LOGRANGE(node, btree, tmp));
1011 btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
1012 }
1013 memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
1014 xfs_da_log_buf(state->args->trans, drop_blk->bp,
1015 XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
1016 be16_add(&node->hdr.count, -1);
1017 xfs_da_log_buf(state->args->trans, drop_blk->bp,
1018 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
1019
1020 /*
1021 * Copy the last hash value from the block to propagate upwards.
1022 */
1023 btree--;
1024 drop_blk->hashval = be32_to_cpu(btree->hashval);
1025 }
1026
1027 /*
1028 * Unbalance the btree elements between two intermediate nodes,
1029 * move all Btree elements from one node into another.
1030 */
1031 STATIC void
1032 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1033 xfs_da_state_blk_t *save_blk)
1034 {
1035 xfs_da_intnode_t *drop_node, *save_node;
1036 xfs_da_node_entry_t *btree;
1037 int tmp;
1038 xfs_trans_t *tp;
1039
1040 drop_node = drop_blk->bp->data;
1041 save_node = save_blk->bp->data;
1042 ASSERT(be16_to_cpu(drop_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1043 ASSERT(be16_to_cpu(save_node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1044 tp = state->args->trans;
1045
1046 /*
1047 * If the dying block has lower hashvals, then move all the
1048 * elements in the remaining block up to make a hole.
1049 */
1050 if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
1051 (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
1052 be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
1053 {
1054 btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
1055 tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1056 memmove(btree, &save_node->btree[0], tmp);
1057 btree = &save_node->btree[0];
1058 xfs_da_log_buf(tp, save_blk->bp,
1059 XFS_DA_LOGRANGE(save_node, btree,
1060 (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
1061 sizeof(xfs_da_node_entry_t)));
1062 } else {
1063 btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
1064 xfs_da_log_buf(tp, save_blk->bp,
1065 XFS_DA_LOGRANGE(save_node, btree,
1066 be16_to_cpu(drop_node->hdr.count) *
1067 sizeof(xfs_da_node_entry_t)));
1068 }
1069
1070 /*
1071 * Move all the B-tree elements from drop_blk to save_blk.
1072 */
1073 tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1074 memcpy(btree, &drop_node->btree[0], tmp);
1075 be16_add(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
1076
1077 xfs_da_log_buf(tp, save_blk->bp,
1078 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1079 sizeof(save_node->hdr)));
1080
1081 /*
1082 * Save the last hashval in the remaining block for upward propagation.
1083 */
1084 save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
1085 }
1086
1087 /*========================================================================
1088 * Routines used for finding things in the Btree.
1089 *========================================================================*/
1090
1091 /*
1092 * Walk down the Btree looking for a particular filename, filling
1093 * in the state structure as we go.
1094 *
1095 * We will set the state structure to point to each of the elements
1096 * in each of the nodes where either the hashval is or should be.
1097 *
1098 * We support duplicate hashval's so for each entry in the current
1099 * node that could contain the desired hashval, descend. This is a
1100 * pruned depth-first tree search.
1101 */
1102 int /* error */
1103 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1104 {
1105 xfs_da_state_blk_t *blk;
1106 xfs_da_blkinfo_t *curr;
1107 xfs_da_intnode_t *node;
1108 xfs_da_node_entry_t *btree;
1109 xfs_dablk_t blkno;
1110 int probe, span, max, error, retval;
1111 xfs_dahash_t hashval;
1112 xfs_da_args_t *args;
1113
1114 args = state->args;
1115
1116 /*
1117 * Descend thru the B-tree searching each level for the right
1118 * node to use, until the right hashval is found.
1119 */
1120 if (args->whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(state->mp))
1121 blkno = state->mp->m_dirleafblk;
1122 else
1123 blkno = 0;
1124 for (blk = &state->path.blk[0], state->path.active = 1;
1125 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1126 blk++, state->path.active++) {
1127 /*
1128 * Read the next node down in the tree.
1129 */
1130 blk->blkno = blkno;
1131 error = xfs_da_read_buf(args->trans, args->dp, blkno,
1132 -1, &blk->bp, args->whichfork);
1133 if (error) {
1134 blk->blkno = 0;
1135 state->path.active--;
1136 return(error);
1137 }
1138 curr = blk->bp->data;
1139 ASSERT(be16_to_cpu(curr->magic) == XFS_DA_NODE_MAGIC ||
1140 be16_to_cpu(curr->magic) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1141 be16_to_cpu(curr->magic) == XFS_ATTR_LEAF_MAGIC);
1142
1143 /*
1144 * Search an intermediate node for a match.
1145 */
1146 blk->magic = be16_to_cpu(curr->magic);
1147 if (blk->magic == XFS_DA_NODE_MAGIC) {
1148 node = blk->bp->data;
1149 blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1150
1151 /*
1152 * Binary search. (note: small blocks will skip loop)
1153 */
1154 max = be16_to_cpu(node->hdr.count);
1155 probe = span = max / 2;
1156 hashval = args->hashval;
1157 for (btree = &node->btree[probe]; span > 4;
1158 btree = &node->btree[probe]) {
1159 span /= 2;
1160 if (be32_to_cpu(btree->hashval) < hashval)
1161 probe += span;
1162 else if (be32_to_cpu(btree->hashval) > hashval)
1163 probe -= span;
1164 else
1165 break;
1166 }
1167 ASSERT((probe >= 0) && (probe < max));
1168 ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1169
1170 /*
1171 * Since we may have duplicate hashval's, find the first
1172 * matching hashval in the node.
1173 */
1174 while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1175 btree--;
1176 probe--;
1177 }
1178 while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1179 btree++;
1180 probe++;
1181 }
1182
1183 /*
1184 * Pick the right block to descend on.
1185 */
1186 if (probe == max) {
1187 blk->index = max-1;
1188 blkno = be32_to_cpu(node->btree[max-1].before);
1189 } else {
1190 blk->index = probe;
1191 blkno = be32_to_cpu(btree->before);
1192 }
1193 }
1194 else if (be16_to_cpu(curr->magic) == XFS_ATTR_LEAF_MAGIC) {
1195 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1196 break;
1197 }
1198 else if (be16_to_cpu(curr->magic) == XFS_DIR_LEAF_MAGIC) {
1199 blk->hashval = xfs_dir_leaf_lasthash(blk->bp, NULL);
1200 break;
1201 }
1202 else if (be16_to_cpu(curr->magic) == XFS_DIR2_LEAFN_MAGIC) {
1203 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1204 break;
1205 }
1206 }
1207
1208 /*
1209 * A leaf block that ends in the hashval that we are interested in
1210 * (final hashval == search hashval) means that the next block may
1211 * contain more entries with the same hashval, shift upward to the
1212 * next leaf and keep searching.
1213 */
1214 for (;;) {
1215 if (blk->magic == XFS_DIR_LEAF_MAGIC) {
1216 ASSERT(XFS_DIR_IS_V1(state->mp));
1217 retval = xfs_dir_leaf_lookup_int(blk->bp, args,
1218 &blk->index);
1219 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1220 ASSERT(XFS_DIR_IS_V2(state->mp));
1221 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1222 &blk->index, state);
1223 }
1224 else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1225 retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1226 blk->index = args->index;
1227 args->blkno = blk->blkno;
1228 }
1229 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1230 (blk->hashval == args->hashval)) {
1231 error = xfs_da_path_shift(state, &state->path, 1, 1,
1232 &retval);
1233 if (error)
1234 return(error);
1235 if (retval == 0) {
1236 continue;
1237 }
1238 else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1239 /* path_shift() gives ENOENT */
1240 retval = XFS_ERROR(ENOATTR);
1241 }
1242 }
1243 break;
1244 }
1245 *result = retval;
1246 return(0);
1247 }
1248
1249 /*========================================================================
1250 * Utility routines.
1251 *========================================================================*/
1252
1253 /*
1254 * Link a new block into a doubly linked list of blocks (of whatever type).
1255 */
1256 int /* error */
1257 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1258 xfs_da_state_blk_t *new_blk)
1259 {
1260 xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1261 xfs_da_args_t *args;
1262 int before=0, error;
1263 xfs_dabuf_t *bp;
1264
1265 /*
1266 * Set up environment.
1267 */
1268 args = state->args;
1269 ASSERT(args != NULL);
1270 old_info = old_blk->bp->data;
1271 new_info = new_blk->bp->data;
1272 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1273 old_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1274 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1275 ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1276 ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1277 ASSERT(old_blk->magic == new_blk->magic);
1278
1279 switch (old_blk->magic) {
1280 case XFS_ATTR_LEAF_MAGIC:
1281 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1282 break;
1283 case XFS_DIR_LEAF_MAGIC:
1284 ASSERT(XFS_DIR_IS_V1(state->mp));
1285 before = xfs_dir_leaf_order(old_blk->bp, new_blk->bp);
1286 break;
1287 case XFS_DIR2_LEAFN_MAGIC:
1288 ASSERT(XFS_DIR_IS_V2(state->mp));
1289 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1290 break;
1291 case XFS_DA_NODE_MAGIC:
1292 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1293 break;
1294 }
1295
1296 /*
1297 * Link blocks in appropriate order.
1298 */
1299 if (before) {
1300 /*
1301 * Link new block in before existing block.
1302 */
1303 new_info->forw = cpu_to_be32(old_blk->blkno);
1304 new_info->back = old_info->back;
1305 if (old_info->back) {
1306 error = xfs_da_read_buf(args->trans, args->dp,
1307 be32_to_cpu(old_info->back),
1308 -1, &bp, args->whichfork);
1309 if (error)
1310 return(error);
1311 ASSERT(bp != NULL);
1312 tmp_info = bp->data;
1313 ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1314 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1315 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1316 xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1317 xfs_da_buf_done(bp);
1318 }
1319 old_info->back = cpu_to_be32(new_blk->blkno);
1320 } else {
1321 /*
1322 * Link new block in after existing block.
1323 */
1324 new_info->forw = old_info->forw;
1325 new_info->back = cpu_to_be32(old_blk->blkno);
1326 if (old_info->forw) {
1327 error = xfs_da_read_buf(args->trans, args->dp,
1328 be32_to_cpu(old_info->forw),
1329 -1, &bp, args->whichfork);
1330 if (error)
1331 return(error);
1332 ASSERT(bp != NULL);
1333 tmp_info = bp->data;
1334 ASSERT(tmp_info->magic == old_info->magic);
1335 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1336 tmp_info->back = cpu_to_be32(new_blk->blkno);
1337 xfs_da_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1338 xfs_da_buf_done(bp);
1339 }
1340 old_info->forw = cpu_to_be32(new_blk->blkno);
1341 }
1342
1343 xfs_da_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1344 xfs_da_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1345 return(0);
1346 }
1347
1348 /*
1349 * Compare two intermediate nodes for "order".
1350 */
1351 STATIC int
1352 xfs_da_node_order(xfs_dabuf_t *node1_bp, xfs_dabuf_t *node2_bp)
1353 {
1354 xfs_da_intnode_t *node1, *node2;
1355
1356 node1 = node1_bp->data;
1357 node2 = node2_bp->data;
1358 ASSERT((be16_to_cpu(node1->hdr.info.magic) == XFS_DA_NODE_MAGIC) &&
1359 (be16_to_cpu(node2->hdr.info.magic) == XFS_DA_NODE_MAGIC));
1360 if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1361 ((be32_to_cpu(node2->btree[0].hashval) <
1362 be32_to_cpu(node1->btree[0].hashval)) ||
1363 (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1364 be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1365 return(1);
1366 }
1367 return(0);
1368 }
1369
1370 /*
1371 * Pick up the last hashvalue from an intermediate node.
1372 */
1373 STATIC uint
1374 xfs_da_node_lasthash(xfs_dabuf_t *bp, int *count)
1375 {
1376 xfs_da_intnode_t *node;
1377
1378 node = bp->data;
1379 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1380 if (count)
1381 *count = be16_to_cpu(node->hdr.count);
1382 if (!node->hdr.count)
1383 return(0);
1384 return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1385 }
1386
1387 /*
1388 * Unlink a block from a doubly linked list of blocks.
1389 */
1390 STATIC int /* error */
1391 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1392 xfs_da_state_blk_t *save_blk)
1393 {
1394 xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1395 xfs_da_args_t *args;
1396 xfs_dabuf_t *bp;
1397 int error;
1398
1399 /*
1400 * Set up environment.
1401 */
1402 args = state->args;
1403 ASSERT(args != NULL);
1404 save_info = save_blk->bp->data;
1405 drop_info = drop_blk->bp->data;
1406 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1407 save_blk->magic == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1408 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1409 ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1410 ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1411 ASSERT(save_blk->magic == drop_blk->magic);
1412 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1413 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1414 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1415 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1416
1417 /*
1418 * Unlink the leaf block from the doubly linked chain of leaves.
1419 */
1420 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1421 save_info->back = drop_info->back;
1422 if (drop_info->back) {
1423 error = xfs_da_read_buf(args->trans, args->dp,
1424 be32_to_cpu(drop_info->back),
1425 -1, &bp, args->whichfork);
1426 if (error)
1427 return(error);
1428 ASSERT(bp != NULL);
1429 tmp_info = bp->data;
1430 ASSERT(tmp_info->magic == save_info->magic);
1431 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1432 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1433 xfs_da_log_buf(args->trans, bp, 0,
1434 sizeof(*tmp_info) - 1);
1435 xfs_da_buf_done(bp);
1436 }
1437 } else {
1438 save_info->forw = drop_info->forw;
1439 if (drop_info->forw) {
1440 error = xfs_da_read_buf(args->trans, args->dp,
1441 be32_to_cpu(drop_info->forw),
1442 -1, &bp, args->whichfork);
1443 if (error)
1444 return(error);
1445 ASSERT(bp != NULL);
1446 tmp_info = bp->data;
1447 ASSERT(tmp_info->magic == save_info->magic);
1448 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1449 tmp_info->back = cpu_to_be32(save_blk->blkno);
1450 xfs_da_log_buf(args->trans, bp, 0,
1451 sizeof(*tmp_info) - 1);
1452 xfs_da_buf_done(bp);
1453 }
1454 }
1455
1456 xfs_da_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1457 return(0);
1458 }
1459
1460 /*
1461 * Move a path "forward" or "!forward" one block at the current level.
1462 *
1463 * This routine will adjust a "path" to point to the next block
1464 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1465 * Btree, including updating pointers to the intermediate nodes between
1466 * the new bottom and the root.
1467 */
1468 int /* error */
1469 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1470 int forward, int release, int *result)
1471 {
1472 xfs_da_state_blk_t *blk;
1473 xfs_da_blkinfo_t *info;
1474 xfs_da_intnode_t *node;
1475 xfs_da_args_t *args;
1476 xfs_dablk_t blkno=0;
1477 int level, error;
1478
1479 /*
1480 * Roll up the Btree looking for the first block where our
1481 * current index is not at the edge of the block. Note that
1482 * we skip the bottom layer because we want the sibling block.
1483 */
1484 args = state->args;
1485 ASSERT(args != NULL);
1486 ASSERT(path != NULL);
1487 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1488 level = (path->active-1) - 1; /* skip bottom layer in path */
1489 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1490 ASSERT(blk->bp != NULL);
1491 node = blk->bp->data;
1492 ASSERT(be16_to_cpu(node->hdr.info.magic) == XFS_DA_NODE_MAGIC);
1493 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1494 blk->index++;
1495 blkno = be32_to_cpu(node->btree[blk->index].before);
1496 break;
1497 } else if (!forward && (blk->index > 0)) {
1498 blk->index--;
1499 blkno = be32_to_cpu(node->btree[blk->index].before);
1500 break;
1501 }
1502 }
1503 if (level < 0) {
1504 *result = XFS_ERROR(ENOENT); /* we're out of our tree */
1505 ASSERT(args->oknoent);
1506 return(0);
1507 }
1508
1509 /*
1510 * Roll down the edge of the subtree until we reach the
1511 * same depth we were at originally.
1512 */
1513 for (blk++, level++; level < path->active; blk++, level++) {
1514 /*
1515 * Release the old block.
1516 * (if it's dirty, trans won't actually let go)
1517 */
1518 if (release)
1519 xfs_da_brelse(args->trans, blk->bp);
1520
1521 /*
1522 * Read the next child block.
1523 */
1524 blk->blkno = blkno;
1525 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1526 &blk->bp, args->whichfork);
1527 if (error)
1528 return(error);
1529 ASSERT(blk->bp != NULL);
1530 info = blk->bp->data;
1531 ASSERT(be16_to_cpu(info->magic) == XFS_DA_NODE_MAGIC ||
1532 be16_to_cpu(info->magic) == XFS_DIRX_LEAF_MAGIC(state->mp) ||
1533 be16_to_cpu(info->magic) == XFS_ATTR_LEAF_MAGIC);
1534 blk->magic = be16_to_cpu(info->magic);
1535 if (blk->magic == XFS_DA_NODE_MAGIC) {
1536 node = (xfs_da_intnode_t *)info;
1537 blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1538 if (forward)
1539 blk->index = 0;
1540 else
1541 blk->index = be16_to_cpu(node->hdr.count)-1;
1542 blkno = be32_to_cpu(node->btree[blk->index].before);
1543 } else {
1544 ASSERT(level == path->active-1);
1545 blk->index = 0;
1546 switch(blk->magic) {
1547 case XFS_ATTR_LEAF_MAGIC:
1548 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1549 NULL);
1550 break;
1551 case XFS_DIR_LEAF_MAGIC:
1552 ASSERT(XFS_DIR_IS_V1(state->mp));
1553 blk->hashval = xfs_dir_leaf_lasthash(blk->bp,
1554 NULL);
1555 break;
1556 case XFS_DIR2_LEAFN_MAGIC:
1557 ASSERT(XFS_DIR_IS_V2(state->mp));
1558 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1559 NULL);
1560 break;
1561 default:
1562 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1563 blk->magic ==
1564 XFS_DIRX_LEAF_MAGIC(state->mp));
1565 break;
1566 }
1567 }
1568 }
1569 *result = 0;
1570 return(0);
1571 }
1572
1573
1574 /*========================================================================
1575 * Utility routines.
1576 *========================================================================*/
1577
1578 /*
1579 * Implement a simple hash on a character string.
1580 * Rotate the hash value by 7 bits, then XOR each character in.
1581 * This is implemented with some source-level loop unrolling.
1582 */
1583 xfs_dahash_t
1584 xfs_da_hashname(const uchar_t *name, int namelen)
1585 {
1586 xfs_dahash_t hash;
1587
1588 /*
1589 * Do four characters at a time as long as we can.
1590 */
1591 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1592 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1593 (name[3] << 0) ^ rol32(hash, 7 * 4);
1594
1595 /*
1596 * Now do the rest of the characters.
1597 */
1598 switch (namelen) {
1599 case 3:
1600 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1601 rol32(hash, 7 * 3);
1602 case 2:
1603 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1604 case 1:
1605 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1606 default: /* case 0: */
1607 return hash;
1608 }
1609 }
1610
1611 /*
1612 * Add a block to the btree ahead of the file.
1613 * Return the new block number to the caller.
1614 */
1615 int
1616 xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno)
1617 {
1618 xfs_fileoff_t bno, b;
1619 xfs_bmbt_irec_t map;
1620 xfs_bmbt_irec_t *mapp;
1621 xfs_inode_t *dp;
1622 int nmap, error, w, count, c, got, i, mapi;
1623 xfs_fsize_t size;
1624 xfs_trans_t *tp;
1625 xfs_mount_t *mp;
1626
1627 dp = args->dp;
1628 mp = dp->i_mount;
1629 w = args->whichfork;
1630 tp = args->trans;
1631 /*
1632 * For new directories adjust the file offset and block count.
1633 */
1634 if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp)) {
1635 bno = mp->m_dirleafblk;
1636 count = mp->m_dirblkfsbs;
1637 } else {
1638 bno = 0;
1639 count = 1;
1640 }
1641 /*
1642 * Find a spot in the file space to put the new block.
1643 */
1644 if ((error = xfs_bmap_first_unused(tp, dp, count, &bno, w))) {
1645 return error;
1646 }
1647 if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
1648 ASSERT(bno >= mp->m_dirleafblk && bno < mp->m_dirfreeblk);
1649 /*
1650 * Try mapping it in one filesystem block.
1651 */
1652 nmap = 1;
1653 ASSERT(args->firstblock != NULL);
1654 if ((error = xfs_bmapi(tp, dp, bno, count,
1655 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|XFS_BMAPI_METADATA|
1656 XFS_BMAPI_CONTIG,
1657 args->firstblock, args->total, &map, &nmap,
1658 args->flist))) {
1659 return error;
1660 }
1661 ASSERT(nmap <= 1);
1662 if (nmap == 1) {
1663 mapp = &map;
1664 mapi = 1;
1665 }
1666 /*
1667 * If we didn't get it and the block might work if fragmented,
1668 * try without the CONTIG flag. Loop until we get it all.
1669 */
1670 else if (nmap == 0 && count > 1) {
1671 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1672 for (b = bno, mapi = 0; b < bno + count; ) {
1673 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1674 c = (int)(bno + count - b);
1675 if ((error = xfs_bmapi(tp, dp, b, c,
1676 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_WRITE|
1677 XFS_BMAPI_METADATA,
1678 args->firstblock, args->total,
1679 &mapp[mapi], &nmap, args->flist))) {
1680 kmem_free(mapp, sizeof(*mapp) * count);
1681 return error;
1682 }
1683 if (nmap < 1)
1684 break;
1685 mapi += nmap;
1686 b = mapp[mapi - 1].br_startoff +
1687 mapp[mapi - 1].br_blockcount;
1688 }
1689 } else {
1690 mapi = 0;
1691 mapp = NULL;
1692 }
1693 /*
1694 * Count the blocks we got, make sure it matches the total.
1695 */
1696 for (i = 0, got = 0; i < mapi; i++)
1697 got += mapp[i].br_blockcount;
1698 if (got != count || mapp[0].br_startoff != bno ||
1699 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1700 bno + count) {
1701 if (mapp != &map)
1702 kmem_free(mapp, sizeof(*mapp) * count);
1703 return XFS_ERROR(ENOSPC);
1704 }
1705 if (mapp != &map)
1706 kmem_free(mapp, sizeof(*mapp) * count);
1707 *new_blkno = (xfs_dablk_t)bno;
1708 /*
1709 * For version 1 directories, adjust the file size if it changed.
1710 */
1711 if (w == XFS_DATA_FORK && XFS_DIR_IS_V1(mp)) {
1712 ASSERT(mapi == 1);
1713 if ((error = xfs_bmap_last_offset(tp, dp, &bno, w)))
1714 return error;
1715 size = XFS_FSB_TO_B(mp, bno);
1716 if (size != dp->i_d.di_size) {
1717 dp->i_d.di_size = size;
1718 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1719 }
1720 }
1721 return 0;
1722 }
1723
1724 /*
1725 * Ick. We need to always be able to remove a btree block, even
1726 * if there's no space reservation because the filesystem is full.
1727 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1728 * It swaps the target block with the last block in the file. The
1729 * last block in the file can always be removed since it can't cause
1730 * a bmap btree split to do that.
1731 */
1732 STATIC int
1733 xfs_da_swap_lastblock(xfs_da_args_t *args, xfs_dablk_t *dead_blknop,
1734 xfs_dabuf_t **dead_bufp)
1735 {
1736 xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1737 xfs_dabuf_t *dead_buf, *last_buf, *sib_buf, *par_buf;
1738 xfs_fileoff_t lastoff;
1739 xfs_inode_t *ip;
1740 xfs_trans_t *tp;
1741 xfs_mount_t *mp;
1742 int error, w, entno, level, dead_level;
1743 xfs_da_blkinfo_t *dead_info, *sib_info;
1744 xfs_da_intnode_t *par_node, *dead_node;
1745 xfs_dir_leafblock_t *dead_leaf;
1746 xfs_dir2_leaf_t *dead_leaf2;
1747 xfs_dahash_t dead_hash;
1748
1749 dead_buf = *dead_bufp;
1750 dead_blkno = *dead_blknop;
1751 tp = args->trans;
1752 ip = args->dp;
1753 w = args->whichfork;
1754 ASSERT(w == XFS_DATA_FORK);
1755 mp = ip->i_mount;
1756 if (XFS_DIR_IS_V2(mp)) {
1757 lastoff = mp->m_dirfreeblk;
1758 error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1759 } else
1760 error = xfs_bmap_last_offset(tp, ip, &lastoff, w);
1761 if (error)
1762 return error;
1763 if (unlikely(lastoff == 0)) {
1764 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1765 mp);
1766 return XFS_ERROR(EFSCORRUPTED);
1767 }
1768 /*
1769 * Read the last block in the btree space.
1770 */
1771 last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1772 if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1773 return error;
1774 /*
1775 * Copy the last block into the dead buffer and log it.
1776 */
1777 memcpy(dead_buf->data, last_buf->data, mp->m_dirblksize);
1778 xfs_da_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1779 dead_info = dead_buf->data;
1780 /*
1781 * Get values from the moved block.
1782 */
1783 if (be16_to_cpu(dead_info->magic) == XFS_DIR_LEAF_MAGIC) {
1784 ASSERT(XFS_DIR_IS_V1(mp));
1785 dead_leaf = (xfs_dir_leafblock_t *)dead_info;
1786 dead_level = 0;
1787 dead_hash =
1788 INT_GET(dead_leaf->entries[INT_GET(dead_leaf->hdr.count, ARCH_CONVERT) - 1].hashval, ARCH_CONVERT);
1789 } else if (be16_to_cpu(dead_info->magic) == XFS_DIR2_LEAFN_MAGIC) {
1790 ASSERT(XFS_DIR_IS_V2(mp));
1791 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1792 dead_level = 0;
1793 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1794 } else {
1795 ASSERT(be16_to_cpu(dead_info->magic) == XFS_DA_NODE_MAGIC);
1796 dead_node = (xfs_da_intnode_t *)dead_info;
1797 dead_level = be16_to_cpu(dead_node->hdr.level);
1798 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1799 }
1800 sib_buf = par_buf = NULL;
1801 /*
1802 * If the moved block has a left sibling, fix up the pointers.
1803 */
1804 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1805 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1806 goto done;
1807 sib_info = sib_buf->data;
1808 if (unlikely(
1809 be32_to_cpu(sib_info->forw) != last_blkno ||
1810 sib_info->magic != dead_info->magic)) {
1811 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1812 XFS_ERRLEVEL_LOW, mp);
1813 error = XFS_ERROR(EFSCORRUPTED);
1814 goto done;
1815 }
1816 sib_info->forw = cpu_to_be32(dead_blkno);
1817 xfs_da_log_buf(tp, sib_buf,
1818 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1819 sizeof(sib_info->forw)));
1820 xfs_da_buf_done(sib_buf);
1821 sib_buf = NULL;
1822 }
1823 /*
1824 * If the moved block has a right sibling, fix up the pointers.
1825 */
1826 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1827 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1828 goto done;
1829 sib_info = sib_buf->data;
1830 if (unlikely(
1831 be32_to_cpu(sib_info->back) != last_blkno ||
1832 sib_info->magic != dead_info->magic)) {
1833 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1834 XFS_ERRLEVEL_LOW, mp);
1835 error = XFS_ERROR(EFSCORRUPTED);
1836 goto done;
1837 }
1838 sib_info->back = cpu_to_be32(dead_blkno);
1839 xfs_da_log_buf(tp, sib_buf,
1840 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1841 sizeof(sib_info->back)));
1842 xfs_da_buf_done(sib_buf);
1843 sib_buf = NULL;
1844 }
1845 par_blkno = XFS_DIR_IS_V1(mp) ? 0 : mp->m_dirleafblk;
1846 level = -1;
1847 /*
1848 * Walk down the tree looking for the parent of the moved block.
1849 */
1850 for (;;) {
1851 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1852 goto done;
1853 par_node = par_buf->data;
1854 if (unlikely(
1855 be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC ||
1856 (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1857 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1858 XFS_ERRLEVEL_LOW, mp);
1859 error = XFS_ERROR(EFSCORRUPTED);
1860 goto done;
1861 }
1862 level = be16_to_cpu(par_node->hdr.level);
1863 for (entno = 0;
1864 entno < be16_to_cpu(par_node->hdr.count) &&
1865 be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1866 entno++)
1867 continue;
1868 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1869 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1870 XFS_ERRLEVEL_LOW, mp);
1871 error = XFS_ERROR(EFSCORRUPTED);
1872 goto done;
1873 }
1874 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1875 if (level == dead_level + 1)
1876 break;
1877 xfs_da_brelse(tp, par_buf);
1878 par_buf = NULL;
1879 }
1880 /*
1881 * We're in the right parent block.
1882 * Look for the right entry.
1883 */
1884 for (;;) {
1885 for (;
1886 entno < be16_to_cpu(par_node->hdr.count) &&
1887 be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1888 entno++)
1889 continue;
1890 if (entno < be16_to_cpu(par_node->hdr.count))
1891 break;
1892 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1893 xfs_da_brelse(tp, par_buf);
1894 par_buf = NULL;
1895 if (unlikely(par_blkno == 0)) {
1896 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1897 XFS_ERRLEVEL_LOW, mp);
1898 error = XFS_ERROR(EFSCORRUPTED);
1899 goto done;
1900 }
1901 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1902 goto done;
1903 par_node = par_buf->data;
1904 if (unlikely(
1905 be16_to_cpu(par_node->hdr.level) != level ||
1906 be16_to_cpu(par_node->hdr.info.magic) != XFS_DA_NODE_MAGIC)) {
1907 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1908 XFS_ERRLEVEL_LOW, mp);
1909 error = XFS_ERROR(EFSCORRUPTED);
1910 goto done;
1911 }
1912 entno = 0;
1913 }
1914 /*
1915 * Update the parent entry pointing to the moved block.
1916 */
1917 par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1918 xfs_da_log_buf(tp, par_buf,
1919 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1920 sizeof(par_node->btree[entno].before)));
1921 xfs_da_buf_done(par_buf);
1922 xfs_da_buf_done(dead_buf);
1923 *dead_blknop = last_blkno;
1924 *dead_bufp = last_buf;
1925 return 0;
1926 done:
1927 if (par_buf)
1928 xfs_da_brelse(tp, par_buf);
1929 if (sib_buf)
1930 xfs_da_brelse(tp, sib_buf);
1931 xfs_da_brelse(tp, last_buf);
1932 return error;
1933 }
1934
1935 /*
1936 * Remove a btree block from a directory or attribute.
1937 */
1938 int
1939 xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1940 xfs_dabuf_t *dead_buf)
1941 {
1942 xfs_inode_t *dp;
1943 int done, error, w, count;
1944 xfs_fileoff_t bno;
1945 xfs_fsize_t size;
1946 xfs_trans_t *tp;
1947 xfs_mount_t *mp;
1948
1949 dp = args->dp;
1950 w = args->whichfork;
1951 tp = args->trans;
1952 mp = dp->i_mount;
1953 if (w == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
1954 count = mp->m_dirblkfsbs;
1955 else
1956 count = 1;
1957 for (;;) {
1958 /*
1959 * Remove extents. If we get ENOSPC for a dir we have to move
1960 * the last block to the place we want to kill.
1961 */
1962 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1963 XFS_BMAPI_AFLAG(w)|XFS_BMAPI_METADATA,
1964 0, args->firstblock, args->flist,
1965 &done)) == ENOSPC) {
1966 if (w != XFS_DATA_FORK)
1967 goto done;
1968 if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1969 &dead_buf)))
1970 goto done;
1971 } else if (error)
1972 goto done;
1973 else
1974 break;
1975 }
1976 ASSERT(done);
1977 xfs_da_binval(tp, dead_buf);
1978 /*
1979 * Adjust the directory size for version 1.
1980 */
1981 if (w == XFS_DATA_FORK && XFS_DIR_IS_V1(mp)) {
1982 if ((error = xfs_bmap_last_offset(tp, dp, &bno, w)))
1983 return error;
1984 size = XFS_FSB_TO_B(dp->i_mount, bno);
1985 if (size != dp->i_d.di_size) {
1986 dp->i_d.di_size = size;
1987 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
1988 }
1989 }
1990 return 0;
1991 done:
1992 xfs_da_binval(tp, dead_buf);
1993 return error;
1994 }
1995
1996 /*
1997 * See if the mapping(s) for this btree block are valid, i.e.
1998 * don't contain holes, are logically contiguous, and cover the whole range.
1999 */
2000 STATIC int
2001 xfs_da_map_covers_blocks(
2002 int nmap,
2003 xfs_bmbt_irec_t *mapp,
2004 xfs_dablk_t bno,
2005 int count)
2006 {
2007 int i;
2008 xfs_fileoff_t off;
2009
2010 for (i = 0, off = bno; i < nmap; i++) {
2011 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
2012 mapp[i].br_startblock == DELAYSTARTBLOCK) {
2013 return 0;
2014 }
2015 if (off != mapp[i].br_startoff) {
2016 return 0;
2017 }
2018 off += mapp[i].br_blockcount;
2019 }
2020 return off == bno + count;
2021 }
2022
2023 /*
2024 * Make a dabuf.
2025 * Used for get_buf, read_buf, read_bufr, and reada_buf.
2026 */
2027 STATIC int
2028 xfs_da_do_buf(
2029 xfs_trans_t *trans,
2030 xfs_inode_t *dp,
2031 xfs_dablk_t bno,
2032 xfs_daddr_t *mappedbnop,
2033 xfs_dabuf_t **bpp,
2034 int whichfork,
2035 int caller,
2036 inst_t *ra)
2037 {
2038 xfs_buf_t *bp = NULL;
2039 xfs_buf_t **bplist;
2040 int error=0;
2041 int i;
2042 xfs_bmbt_irec_t map;
2043 xfs_bmbt_irec_t *mapp;
2044 xfs_daddr_t mappedbno;
2045 xfs_mount_t *mp;
2046 int nbplist=0;
2047 int nfsb;
2048 int nmap;
2049 xfs_dabuf_t *rbp;
2050
2051 mp = dp->i_mount;
2052 if (whichfork == XFS_DATA_FORK && XFS_DIR_IS_V2(mp))
2053 nfsb = mp->m_dirblkfsbs;
2054 else
2055 nfsb = 1;
2056 mappedbno = *mappedbnop;
2057 /*
2058 * Caller doesn't have a mapping. -2 means don't complain
2059 * if we land in a hole.
2060 */
2061 if (mappedbno == -1 || mappedbno == -2) {
2062 /*
2063 * Optimize the one-block case.
2064 */
2065 if (nfsb == 1) {
2066 xfs_fsblock_t fsb;
2067
2068 if ((error =
2069 xfs_bmapi_single(trans, dp, whichfork, &fsb,
2070 (xfs_fileoff_t)bno))) {
2071 return error;
2072 }
2073 mapp = &map;
2074 if (fsb == NULLFSBLOCK) {
2075 nmap = 0;
2076 } else {
2077 map.br_startblock = fsb;
2078 map.br_startoff = (xfs_fileoff_t)bno;
2079 map.br_blockcount = 1;
2080 nmap = 1;
2081 }
2082 } else {
2083 mapp = kmem_alloc(sizeof(*mapp) * nfsb, KM_SLEEP);
2084 nmap = nfsb;
2085 if ((error = xfs_bmapi(trans, dp, (xfs_fileoff_t)bno,
2086 nfsb,
2087 XFS_BMAPI_METADATA |
2088 XFS_BMAPI_AFLAG(whichfork),
2089 NULL, 0, mapp, &nmap, NULL)))
2090 goto exit0;
2091 }
2092 } else {
2093 map.br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2094 map.br_startoff = (xfs_fileoff_t)bno;
2095 map.br_blockcount = nfsb;
2096 mapp = &map;
2097 nmap = 1;
2098 }
2099 if (!xfs_da_map_covers_blocks(nmap, mapp, bno, nfsb)) {
2100 error = mappedbno == -2 ? 0 : XFS_ERROR(EFSCORRUPTED);
2101 if (unlikely(error == EFSCORRUPTED)) {
2102 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2103 int i;
2104 cmn_err(CE_ALERT, "xfs_da_do_buf: bno %lld\n",
2105 (long long)bno);
2106 cmn_err(CE_ALERT, "dir: inode %lld\n",
2107 (long long)dp->i_ino);
2108 for (i = 0; i < nmap; i++) {
2109 cmn_err(CE_ALERT,
2110 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d\n",
2111 i,
2112 (long long)mapp[i].br_startoff,
2113 (long long)mapp[i].br_startblock,
2114 (long long)mapp[i].br_blockcount,
2115 mapp[i].br_state);
2116 }
2117 }
2118 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2119 XFS_ERRLEVEL_LOW, mp);
2120 }
2121 goto exit0;
2122 }
2123 if (caller != 3 && nmap > 1) {
2124 bplist = kmem_alloc(sizeof(*bplist) * nmap, KM_SLEEP);
2125 nbplist = 0;
2126 } else
2127 bplist = NULL;
2128 /*
2129 * Turn the mapping(s) into buffer(s).
2130 */
2131 for (i = 0; i < nmap; i++) {
2132 int nmapped;
2133
2134 mappedbno = XFS_FSB_TO_DADDR(mp, mapp[i].br_startblock);
2135 if (i == 0)
2136 *mappedbnop = mappedbno;
2137 nmapped = (int)XFS_FSB_TO_BB(mp, mapp[i].br_blockcount);
2138 switch (caller) {
2139 case 0:
2140 bp = xfs_trans_get_buf(trans, mp->m_ddev_targp,
2141 mappedbno, nmapped, 0);
2142 error = bp ? XFS_BUF_GETERROR(bp) : XFS_ERROR(EIO);
2143 break;
2144 case 1:
2145 case 2:
2146 bp = NULL;
2147 error = xfs_trans_read_buf(mp, trans, mp->m_ddev_targp,
2148 mappedbno, nmapped, 0, &bp);
2149 break;
2150 case 3:
2151 xfs_baread(mp->m_ddev_targp, mappedbno, nmapped);
2152 error = 0;
2153 bp = NULL;
2154 break;
2155 }
2156 if (error) {
2157 if (bp)
2158 xfs_trans_brelse(trans, bp);
2159 goto exit1;
2160 }
2161 if (!bp)
2162 continue;
2163 if (caller == 1) {
2164 if (whichfork == XFS_ATTR_FORK) {
2165 XFS_BUF_SET_VTYPE_REF(bp, B_FS_ATTR_BTREE,
2166 XFS_ATTR_BTREE_REF);
2167 } else {
2168 XFS_BUF_SET_VTYPE_REF(bp, B_FS_DIR_BTREE,
2169 XFS_DIR_BTREE_REF);
2170 }
2171 }
2172 if (bplist) {
2173 bplist[nbplist++] = bp;
2174 }
2175 }
2176 /*
2177 * Build a dabuf structure.
2178 */
2179 if (bplist) {
2180 rbp = xfs_da_buf_make(nbplist, bplist, ra);
2181 } else if (bp)
2182 rbp = xfs_da_buf_make(1, &bp, ra);
2183 else
2184 rbp = NULL;
2185 /*
2186 * For read_buf, check the magic number.
2187 */
2188 if (caller == 1) {
2189 xfs_dir2_data_t *data;
2190 xfs_dir2_free_t *free;
2191 xfs_da_blkinfo_t *info;
2192 uint magic, magic1;
2193
2194 info = rbp->data;
2195 data = rbp->data;
2196 free = rbp->data;
2197 magic = be16_to_cpu(info->magic);
2198 magic1 = be32_to_cpu(data->hdr.magic);
2199 if (unlikely(
2200 XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2201 (magic != XFS_DIR_LEAF_MAGIC) &&
2202 (magic != XFS_ATTR_LEAF_MAGIC) &&
2203 (magic != XFS_DIR2_LEAF1_MAGIC) &&
2204 (magic != XFS_DIR2_LEAFN_MAGIC) &&
2205 (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2206 (magic1 != XFS_DIR2_DATA_MAGIC) &&
2207 (be32_to_cpu(free->hdr.magic) != XFS_DIR2_FREE_MAGIC),
2208 mp, XFS_ERRTAG_DA_READ_BUF,
2209 XFS_RANDOM_DA_READ_BUF))) {
2210 xfs_buftrace("DA READ ERROR", rbp->bps[0]);
2211 XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2212 XFS_ERRLEVEL_LOW, mp, info);
2213 error = XFS_ERROR(EFSCORRUPTED);
2214 xfs_da_brelse(trans, rbp);
2215 nbplist = 0;
2216 goto exit1;
2217 }
2218 }
2219 if (bplist) {
2220 kmem_free(bplist, sizeof(*bplist) * nmap);
2221 }
2222 if (mapp != &map) {
2223 kmem_free(mapp, sizeof(*mapp) * nfsb);
2224 }
2225 if (bpp)
2226 *bpp = rbp;
2227 return 0;
2228 exit1:
2229 if (bplist) {
2230 for (i = 0; i < nbplist; i++)
2231 xfs_trans_brelse(trans, bplist[i]);
2232 kmem_free(bplist, sizeof(*bplist) * nmap);
2233 }
2234 exit0:
2235 if (mapp != &map)
2236 kmem_free(mapp, sizeof(*mapp) * nfsb);
2237 if (bpp)
2238 *bpp = NULL;
2239 return error;
2240 }
2241
2242 /*
2243 * Get a buffer for the dir/attr block.
2244 */
2245 int
2246 xfs_da_get_buf(
2247 xfs_trans_t *trans,
2248 xfs_inode_t *dp,
2249 xfs_dablk_t bno,
2250 xfs_daddr_t mappedbno,
2251 xfs_dabuf_t **bpp,
2252 int whichfork)
2253 {
2254 return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 0,
2255 (inst_t *)__return_address);
2256 }
2257
2258 /*
2259 * Get a buffer for the dir/attr block, fill in the contents.
2260 */
2261 int
2262 xfs_da_read_buf(
2263 xfs_trans_t *trans,
2264 xfs_inode_t *dp,
2265 xfs_dablk_t bno,
2266 xfs_daddr_t mappedbno,
2267 xfs_dabuf_t **bpp,
2268 int whichfork)
2269 {
2270 return xfs_da_do_buf(trans, dp, bno, &mappedbno, bpp, whichfork, 1,
2271 (inst_t *)__return_address);
2272 }
2273
2274 /*
2275 * Readahead the dir/attr block.
2276 */
2277 xfs_daddr_t
2278 xfs_da_reada_buf(
2279 xfs_trans_t *trans,
2280 xfs_inode_t *dp,
2281 xfs_dablk_t bno,
2282 int whichfork)
2283 {
2284 xfs_daddr_t rval;
2285
2286 rval = -1;
2287 if (xfs_da_do_buf(trans, dp, bno, &rval, NULL, whichfork, 3,
2288 (inst_t *)__return_address))
2289 return -1;
2290 else
2291 return rval;
2292 }
2293
2294 /*
2295 * Calculate the number of bits needed to hold i different values.
2296 */
2297 uint
2298 xfs_da_log2_roundup(uint i)
2299 {
2300 uint rval;
2301
2302 for (rval = 0; rval < NBBY * sizeof(i); rval++) {
2303 if ((1 << rval) >= i)
2304 break;
2305 }
2306 return(rval);
2307 }
2308
2309 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2310 kmem_zone_t *xfs_dabuf_zone; /* dabuf zone */
2311
2312 /*
2313 * Allocate a dir-state structure.
2314 * We don't put them on the stack since they're large.
2315 */
2316 xfs_da_state_t *
2317 xfs_da_state_alloc(void)
2318 {
2319 return kmem_zone_zalloc(xfs_da_state_zone, KM_SLEEP);
2320 }
2321
2322 /*
2323 * Kill the altpath contents of a da-state structure.
2324 */
2325 STATIC void
2326 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2327 {
2328 int i;
2329
2330 for (i = 0; i < state->altpath.active; i++) {
2331 if (state->altpath.blk[i].bp) {
2332 if (state->altpath.blk[i].bp != state->path.blk[i].bp)
2333 xfs_da_buf_done(state->altpath.blk[i].bp);
2334 state->altpath.blk[i].bp = NULL;
2335 }
2336 }
2337 state->altpath.active = 0;
2338 }
2339
2340 /*
2341 * Free a da-state structure.
2342 */
2343 void
2344 xfs_da_state_free(xfs_da_state_t *state)
2345 {
2346 int i;
2347
2348 xfs_da_state_kill_altpath(state);
2349 for (i = 0; i < state->path.active; i++) {
2350 if (state->path.blk[i].bp)
2351 xfs_da_buf_done(state->path.blk[i].bp);
2352 }
2353 if (state->extravalid && state->extrablk.bp)
2354 xfs_da_buf_done(state->extrablk.bp);
2355 #ifdef DEBUG
2356 memset((char *)state, 0, sizeof(*state));
2357 #endif /* DEBUG */
2358 kmem_zone_free(xfs_da_state_zone, state);
2359 }
2360
2361 #ifdef XFS_DABUF_DEBUG
2362 xfs_dabuf_t *xfs_dabuf_global_list;
2363 lock_t xfs_dabuf_global_lock;
2364 #endif
2365
2366 /*
2367 * Create a dabuf.
2368 */
2369 /* ARGSUSED */
2370 STATIC xfs_dabuf_t *
2371 xfs_da_buf_make(int nbuf, xfs_buf_t **bps, inst_t *ra)
2372 {
2373 xfs_buf_t *bp;
2374 xfs_dabuf_t *dabuf;
2375 int i;
2376 int off;
2377
2378 if (nbuf == 1)
2379 dabuf = kmem_zone_alloc(xfs_dabuf_zone, KM_SLEEP);
2380 else
2381 dabuf = kmem_alloc(XFS_DA_BUF_SIZE(nbuf), KM_SLEEP);
2382 dabuf->dirty = 0;
2383 #ifdef XFS_DABUF_DEBUG
2384 dabuf->ra = ra;
2385 dabuf->target = XFS_BUF_TARGET(bps[0]);
2386 dabuf->blkno = XFS_BUF_ADDR(bps[0]);
2387 #endif
2388 if (nbuf == 1) {
2389 dabuf->nbuf = 1;
2390 bp = bps[0];
2391 dabuf->bbcount = (short)BTOBB(XFS_BUF_COUNT(bp));
2392 dabuf->data = XFS_BUF_PTR(bp);
2393 dabuf->bps[0] = bp;
2394 } else {
2395 dabuf->nbuf = nbuf;
2396 for (i = 0, dabuf->bbcount = 0; i < nbuf; i++) {
2397 dabuf->bps[i] = bp = bps[i];
2398 dabuf->bbcount += BTOBB(XFS_BUF_COUNT(bp));
2399 }
2400 dabuf->data = kmem_alloc(BBTOB(dabuf->bbcount), KM_SLEEP);
2401 for (i = off = 0; i < nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2402 bp = bps[i];
2403 memcpy((char *)dabuf->data + off, XFS_BUF_PTR(bp),
2404 XFS_BUF_COUNT(bp));
2405 }
2406 }
2407 #ifdef XFS_DABUF_DEBUG
2408 {
2409 SPLDECL(s);
2410 xfs_dabuf_t *p;
2411
2412 s = mutex_spinlock(&xfs_dabuf_global_lock);
2413 for (p = xfs_dabuf_global_list; p; p = p->next) {
2414 ASSERT(p->blkno != dabuf->blkno ||
2415 p->target != dabuf->target);
2416 }
2417 dabuf->prev = NULL;
2418 if (xfs_dabuf_global_list)
2419 xfs_dabuf_global_list->prev = dabuf;
2420 dabuf->next = xfs_dabuf_global_list;
2421 xfs_dabuf_global_list = dabuf;
2422 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2423 }
2424 #endif
2425 return dabuf;
2426 }
2427
2428 /*
2429 * Un-dirty a dabuf.
2430 */
2431 STATIC void
2432 xfs_da_buf_clean(xfs_dabuf_t *dabuf)
2433 {
2434 xfs_buf_t *bp;
2435 int i;
2436 int off;
2437
2438 if (dabuf->dirty) {
2439 ASSERT(dabuf->nbuf > 1);
2440 dabuf->dirty = 0;
2441 for (i = off = 0; i < dabuf->nbuf;
2442 i++, off += XFS_BUF_COUNT(bp)) {
2443 bp = dabuf->bps[i];
2444 memcpy(XFS_BUF_PTR(bp), (char *)dabuf->data + off,
2445 XFS_BUF_COUNT(bp));
2446 }
2447 }
2448 }
2449
2450 /*
2451 * Release a dabuf.
2452 */
2453 void
2454 xfs_da_buf_done(xfs_dabuf_t *dabuf)
2455 {
2456 ASSERT(dabuf);
2457 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2458 if (dabuf->dirty)
2459 xfs_da_buf_clean(dabuf);
2460 if (dabuf->nbuf > 1)
2461 kmem_free(dabuf->data, BBTOB(dabuf->bbcount));
2462 #ifdef XFS_DABUF_DEBUG
2463 {
2464 SPLDECL(s);
2465
2466 s = mutex_spinlock(&xfs_dabuf_global_lock);
2467 if (dabuf->prev)
2468 dabuf->prev->next = dabuf->next;
2469 else
2470 xfs_dabuf_global_list = dabuf->next;
2471 if (dabuf->next)
2472 dabuf->next->prev = dabuf->prev;
2473 mutex_spinunlock(&xfs_dabuf_global_lock, s);
2474 }
2475 memset(dabuf, 0, XFS_DA_BUF_SIZE(dabuf->nbuf));
2476 #endif
2477 if (dabuf->nbuf == 1)
2478 kmem_zone_free(xfs_dabuf_zone, dabuf);
2479 else
2480 kmem_free(dabuf, XFS_DA_BUF_SIZE(dabuf->nbuf));
2481 }
2482
2483 /*
2484 * Log transaction from a dabuf.
2485 */
2486 void
2487 xfs_da_log_buf(xfs_trans_t *tp, xfs_dabuf_t *dabuf, uint first, uint last)
2488 {
2489 xfs_buf_t *bp;
2490 uint f;
2491 int i;
2492 uint l;
2493 int off;
2494
2495 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2496 if (dabuf->nbuf == 1) {
2497 ASSERT(dabuf->data == (void *)XFS_BUF_PTR(dabuf->bps[0]));
2498 xfs_trans_log_buf(tp, dabuf->bps[0], first, last);
2499 return;
2500 }
2501 dabuf->dirty = 1;
2502 ASSERT(first <= last);
2503 for (i = off = 0; i < dabuf->nbuf; i++, off += XFS_BUF_COUNT(bp)) {
2504 bp = dabuf->bps[i];
2505 f = off;
2506 l = f + XFS_BUF_COUNT(bp) - 1;
2507 if (f < first)
2508 f = first;
2509 if (l > last)
2510 l = last;
2511 if (f <= l)
2512 xfs_trans_log_buf(tp, bp, f - off, l - off);
2513 /*
2514 * B_DONE is set by xfs_trans_log buf.
2515 * If we don't set it on a new buffer (get not read)
2516 * then if we don't put anything in the buffer it won't
2517 * be set, and at commit it it released into the cache,
2518 * and then a read will fail.
2519 */
2520 else if (!(XFS_BUF_ISDONE(bp)))
2521 XFS_BUF_DONE(bp);
2522 }
2523 ASSERT(last < off);
2524 }
2525
2526 /*
2527 * Release dabuf from a transaction.
2528 * Have to free up the dabuf before the buffers are released,
2529 * since the synchronization on the dabuf is really the lock on the buffer.
2530 */
2531 void
2532 xfs_da_brelse(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2533 {
2534 xfs_buf_t *bp;
2535 xfs_buf_t **bplist;
2536 int i;
2537 int nbuf;
2538
2539 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2540 if ((nbuf = dabuf->nbuf) == 1) {
2541 bplist = &bp;
2542 bp = dabuf->bps[0];
2543 } else {
2544 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2545 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2546 }
2547 xfs_da_buf_done(dabuf);
2548 for (i = 0; i < nbuf; i++)
2549 xfs_trans_brelse(tp, bplist[i]);
2550 if (bplist != &bp)
2551 kmem_free(bplist, nbuf * sizeof(*bplist));
2552 }
2553
2554 /*
2555 * Invalidate dabuf from a transaction.
2556 */
2557 void
2558 xfs_da_binval(xfs_trans_t *tp, xfs_dabuf_t *dabuf)
2559 {
2560 xfs_buf_t *bp;
2561 xfs_buf_t **bplist;
2562 int i;
2563 int nbuf;
2564
2565 ASSERT(dabuf->nbuf && dabuf->data && dabuf->bbcount && dabuf->bps[0]);
2566 if ((nbuf = dabuf->nbuf) == 1) {
2567 bplist = &bp;
2568 bp = dabuf->bps[0];
2569 } else {
2570 bplist = kmem_alloc(nbuf * sizeof(*bplist), KM_SLEEP);
2571 memcpy(bplist, dabuf->bps, nbuf * sizeof(*bplist));
2572 }
2573 xfs_da_buf_done(dabuf);
2574 for (i = 0; i < nbuf; i++)
2575 xfs_trans_binval(tp, bplist[i]);
2576 if (bplist != &bp)
2577 kmem_free(bplist, nbuf * sizeof(*bplist));
2578 }
2579
2580 /*
2581 * Get the first daddr from a dabuf.
2582 */
2583 xfs_daddr_t
2584 xfs_da_blkno(xfs_dabuf_t *dabuf)
2585 {
2586 ASSERT(dabuf->nbuf);
2587 ASSERT(dabuf->data);
2588 return XFS_BUF_ADDR(dabuf->bps[0]);
2589 }
USB Experimental Work