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drm/nouveau: add missing pll_calc calls
[linux-2.6/libata-dev.git] / fs / xfs / xfs_da_btree.c
blob7bfb7dd334fc0442204ce6e483f1fc5ba4dee65f
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_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_dir2.h"
30 #include "xfs_dir2_format.h"
31 #include "xfs_dir2_priv.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_inode_item.h"
35 #include "xfs_alloc.h"
36 #include "xfs_bmap.h"
37 #include "xfs_attr.h"
38 #include "xfs_attr_leaf.h"
39 #include "xfs_error.h"
40 #include "xfs_trace.h"
41
42 /*
43 * xfs_da_btree.c
44 *
45 * Routines to implement directories as Btrees of hashed names.
46 */
47
48 /*========================================================================
49 * Function prototypes for the kernel.
50 *========================================================================*/
51
52 /*
53 * Routines used for growing the Btree.
54 */
55 STATIC int xfs_da_root_split(xfs_da_state_t *state,
56 xfs_da_state_blk_t *existing_root,
57 xfs_da_state_blk_t *new_child);
58 STATIC int xfs_da_node_split(xfs_da_state_t *state,
59 xfs_da_state_blk_t *existing_blk,
60 xfs_da_state_blk_t *split_blk,
61 xfs_da_state_blk_t *blk_to_add,
62 int treelevel,
63 int *result);
64 STATIC void xfs_da_node_rebalance(xfs_da_state_t *state,
65 xfs_da_state_blk_t *node_blk_1,
66 xfs_da_state_blk_t *node_blk_2);
67 STATIC void xfs_da_node_add(xfs_da_state_t *state,
68 xfs_da_state_blk_t *old_node_blk,
69 xfs_da_state_blk_t *new_node_blk);
70
71 /*
72 * Routines used for shrinking the Btree.
73 */
74 STATIC int xfs_da_root_join(xfs_da_state_t *state,
75 xfs_da_state_blk_t *root_blk);
76 STATIC int xfs_da_node_toosmall(xfs_da_state_t *state, int *retval);
77 STATIC void xfs_da_node_remove(xfs_da_state_t *state,
78 xfs_da_state_blk_t *drop_blk);
79 STATIC void xfs_da_node_unbalance(xfs_da_state_t *state,
80 xfs_da_state_blk_t *src_node_blk,
81 xfs_da_state_blk_t *dst_node_blk);
82
83 /*
84 * Utility routines.
85 */
86 STATIC uint xfs_da_node_lasthash(struct xfs_buf *bp, int *count);
87 STATIC int xfs_da_node_order(struct xfs_buf *node1_bp,
88 struct xfs_buf *node2_bp);
89 STATIC int xfs_da_blk_unlink(xfs_da_state_t *state,
90 xfs_da_state_blk_t *drop_blk,
91 xfs_da_state_blk_t *save_blk);
92 STATIC void xfs_da_state_kill_altpath(xfs_da_state_t *state);
93
94 /*========================================================================
95 * Routines used for growing the Btree.
96 *========================================================================*/
97
98 /*
99 * Create the initial contents of an intermediate node.
100 */
101 int
102 xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
103 struct xfs_buf **bpp, int whichfork)
104 {
105 xfs_da_intnode_t *node;
106 struct xfs_buf *bp;
107 int error;
108 xfs_trans_t *tp;
109
110 trace_xfs_da_node_create(args);
111
112 tp = args->trans;
113 error = xfs_da_get_buf(tp, args->dp, blkno, -1, &bp, whichfork);
114 if (error)
115 return(error);
116 ASSERT(bp != NULL);
117 node = bp->b_addr;
118 node->hdr.info.forw = 0;
119 node->hdr.info.back = 0;
120 node->hdr.info.magic = cpu_to_be16(XFS_DA_NODE_MAGIC);
121 node->hdr.info.pad = 0;
122 node->hdr.count = 0;
123 node->hdr.level = cpu_to_be16(level);
124
125 xfs_trans_log_buf(tp, bp,
126 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
127
128 *bpp = bp;
129 return(0);
130 }
131
132 /*
133 * Split a leaf node, rebalance, then possibly split
134 * intermediate nodes, rebalance, etc.
135 */
136 int /* error */
137 xfs_da_split(xfs_da_state_t *state)
138 {
139 xfs_da_state_blk_t *oldblk, *newblk, *addblk;
140 xfs_da_intnode_t *node;
141 struct xfs_buf *bp;
142 int max, action, error, i;
143
144 trace_xfs_da_split(state->args);
145
146 /*
147 * Walk back up the tree splitting/inserting/adjusting as necessary.
148 * If we need to insert and there isn't room, split the node, then
149 * decide which fragment to insert the new block from below into.
150 * Note that we may split the root this way, but we need more fixup.
151 */
152 max = state->path.active - 1;
153 ASSERT((max >= 0) && (max < XFS_DA_NODE_MAXDEPTH));
154 ASSERT(state->path.blk[max].magic == XFS_ATTR_LEAF_MAGIC ||
155 state->path.blk[max].magic == XFS_DIR2_LEAFN_MAGIC);
156
157 addblk = &state->path.blk[max]; /* initial dummy value */
158 for (i = max; (i >= 0) && addblk; state->path.active--, i--) {
159 oldblk = &state->path.blk[i];
160 newblk = &state->altpath.blk[i];
161
162 /*
163 * If a leaf node then
164 * Allocate a new leaf node, then rebalance across them.
165 * else if an intermediate node then
166 * We split on the last layer, must we split the node?
167 */
168 switch (oldblk->magic) {
169 case XFS_ATTR_LEAF_MAGIC:
170 error = xfs_attr_leaf_split(state, oldblk, newblk);
171 if ((error != 0) && (error != ENOSPC)) {
172 return(error); /* GROT: attr is inconsistent */
173 }
174 if (!error) {
175 addblk = newblk;
176 break;
177 }
178 /*
179 * Entry wouldn't fit, split the leaf again.
180 */
181 state->extravalid = 1;
182 if (state->inleaf) {
183 state->extraafter = 0; /* before newblk */
184 trace_xfs_attr_leaf_split_before(state->args);
185 error = xfs_attr_leaf_split(state, oldblk,
186 &state->extrablk);
187 } else {
188 state->extraafter = 1; /* after newblk */
189 trace_xfs_attr_leaf_split_after(state->args);
190 error = xfs_attr_leaf_split(state, newblk,
191 &state->extrablk);
192 }
193 if (error)
194 return(error); /* GROT: attr inconsistent */
195 addblk = newblk;
196 break;
197 case XFS_DIR2_LEAFN_MAGIC:
198 error = xfs_dir2_leafn_split(state, oldblk, newblk);
199 if (error)
200 return error;
201 addblk = newblk;
202 break;
203 case XFS_DA_NODE_MAGIC:
204 error = xfs_da_node_split(state, oldblk, newblk, addblk,
205 max - i, &action);
206 addblk->bp = NULL;
207 if (error)
208 return(error); /* GROT: dir is inconsistent */
209 /*
210 * Record the newly split block for the next time thru?
211 */
212 if (action)
213 addblk = newblk;
214 else
215 addblk = NULL;
216 break;
217 }
218
219 /*
220 * Update the btree to show the new hashval for this child.
221 */
222 xfs_da_fixhashpath(state, &state->path);
223 }
224 if (!addblk)
225 return(0);
226
227 /*
228 * Split the root node.
229 */
230 ASSERT(state->path.active == 0);
231 oldblk = &state->path.blk[0];
232 error = xfs_da_root_split(state, oldblk, addblk);
233 if (error) {
234 addblk->bp = NULL;
235 return(error); /* GROT: dir is inconsistent */
236 }
237
238 /*
239 * Update pointers to the node which used to be block 0 and
240 * just got bumped because of the addition of a new root node.
241 * There might be three blocks involved if a double split occurred,
242 * and the original block 0 could be at any position in the list.
243 */
244
245 node = oldblk->bp->b_addr;
246 if (node->hdr.info.forw) {
247 if (be32_to_cpu(node->hdr.info.forw) == addblk->blkno) {
248 bp = addblk->bp;
249 } else {
250 ASSERT(state->extravalid);
251 bp = state->extrablk.bp;
252 }
253 node = bp->b_addr;
254 node->hdr.info.back = cpu_to_be32(oldblk->blkno);
255 xfs_trans_log_buf(state->args->trans, bp,
256 XFS_DA_LOGRANGE(node, &node->hdr.info,
257 sizeof(node->hdr.info)));
258 }
259 node = oldblk->bp->b_addr;
260 if (node->hdr.info.back) {
261 if (be32_to_cpu(node->hdr.info.back) == addblk->blkno) {
262 bp = addblk->bp;
263 } else {
264 ASSERT(state->extravalid);
265 bp = state->extrablk.bp;
266 }
267 node = bp->b_addr;
268 node->hdr.info.forw = cpu_to_be32(oldblk->blkno);
269 xfs_trans_log_buf(state->args->trans, bp,
270 XFS_DA_LOGRANGE(node, &node->hdr.info,
271 sizeof(node->hdr.info)));
272 }
273 addblk->bp = NULL;
274 return(0);
275 }
276
277 /*
278 * Split the root. We have to create a new root and point to the two
279 * parts (the split old root) that we just created. Copy block zero to
280 * the EOF, extending the inode in process.
281 */
282 STATIC int /* error */
283 xfs_da_root_split(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
284 xfs_da_state_blk_t *blk2)
285 {
286 xfs_da_intnode_t *node, *oldroot;
287 xfs_da_args_t *args;
288 xfs_dablk_t blkno;
289 struct xfs_buf *bp;
290 int error, size;
291 xfs_inode_t *dp;
292 xfs_trans_t *tp;
293 xfs_mount_t *mp;
294 xfs_dir2_leaf_t *leaf;
295
296 trace_xfs_da_root_split(state->args);
297
298 /*
299 * Copy the existing (incorrect) block from the root node position
300 * to a free space somewhere.
301 */
302 args = state->args;
303 ASSERT(args != NULL);
304 error = xfs_da_grow_inode(args, &blkno);
305 if (error)
306 return(error);
307 dp = args->dp;
308 tp = args->trans;
309 mp = state->mp;
310 error = xfs_da_get_buf(tp, dp, blkno, -1, &bp, args->whichfork);
311 if (error)
312 return(error);
313 ASSERT(bp != NULL);
314 node = bp->b_addr;
315 oldroot = blk1->bp->b_addr;
316 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC)) {
317 size = (int)((char *)&oldroot->btree[be16_to_cpu(oldroot->hdr.count)] -
318 (char *)oldroot);
319 } else {
320 ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC));
321 leaf = (xfs_dir2_leaf_t *)oldroot;
322 size = (int)((char *)&leaf->ents[be16_to_cpu(leaf->hdr.count)] -
323 (char *)leaf);
324 }
325 memcpy(node, oldroot, size);
326 xfs_trans_log_buf(tp, bp, 0, size - 1);
327 blk1->bp = bp;
328 blk1->blkno = blkno;
329
330 /*
331 * Set up the new root node.
332 */
333 error = xfs_da_node_create(args,
334 (args->whichfork == XFS_DATA_FORK) ? mp->m_dirleafblk : 0,
335 be16_to_cpu(node->hdr.level) + 1, &bp, args->whichfork);
336 if (error)
337 return(error);
338 node = bp->b_addr;
339 node->btree[0].hashval = cpu_to_be32(blk1->hashval);
340 node->btree[0].before = cpu_to_be32(blk1->blkno);
341 node->btree[1].hashval = cpu_to_be32(blk2->hashval);
342 node->btree[1].before = cpu_to_be32(blk2->blkno);
343 node->hdr.count = cpu_to_be16(2);
344
345 #ifdef DEBUG
346 if (oldroot->hdr.info.magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) {
347 ASSERT(blk1->blkno >= mp->m_dirleafblk &&
348 blk1->blkno < mp->m_dirfreeblk);
349 ASSERT(blk2->blkno >= mp->m_dirleafblk &&
350 blk2->blkno < mp->m_dirfreeblk);
351 }
352 #endif
353
354 /* Header is already logged by xfs_da_node_create */
355 xfs_trans_log_buf(tp, bp,
356 XFS_DA_LOGRANGE(node, node->btree,
357 sizeof(xfs_da_node_entry_t) * 2));
358
359 return(0);
360 }
361
362 /*
363 * Split the node, rebalance, then add the new entry.
364 */
365 STATIC int /* error */
366 xfs_da_node_split(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
367 xfs_da_state_blk_t *newblk,
368 xfs_da_state_blk_t *addblk,
369 int treelevel, int *result)
370 {
371 xfs_da_intnode_t *node;
372 xfs_dablk_t blkno;
373 int newcount, error;
374 int useextra;
375
376 trace_xfs_da_node_split(state->args);
377
378 node = oldblk->bp->b_addr;
379 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
380
381 /*
382 * With V2 dirs the extra block is data or freespace.
383 */
384 useextra = state->extravalid && state->args->whichfork == XFS_ATTR_FORK;
385 newcount = 1 + useextra;
386 /*
387 * Do we have to split the node?
388 */
389 if ((be16_to_cpu(node->hdr.count) + newcount) > state->node_ents) {
390 /*
391 * Allocate a new node, add to the doubly linked chain of
392 * nodes, then move some of our excess entries into it.
393 */
394 error = xfs_da_grow_inode(state->args, &blkno);
395 if (error)
396 return(error); /* GROT: dir is inconsistent */
397
398 error = xfs_da_node_create(state->args, blkno, treelevel,
399 &newblk->bp, state->args->whichfork);
400 if (error)
401 return(error); /* GROT: dir is inconsistent */
402 newblk->blkno = blkno;
403 newblk->magic = XFS_DA_NODE_MAGIC;
404 xfs_da_node_rebalance(state, oldblk, newblk);
405 error = xfs_da_blk_link(state, oldblk, newblk);
406 if (error)
407 return(error);
408 *result = 1;
409 } else {
410 *result = 0;
411 }
412
413 /*
414 * Insert the new entry(s) into the correct block
415 * (updating last hashval in the process).
416 *
417 * xfs_da_node_add() inserts BEFORE the given index,
418 * and as a result of using node_lookup_int() we always
419 * point to a valid entry (not after one), but a split
420 * operation always results in a new block whose hashvals
421 * FOLLOW the current block.
422 *
423 * If we had double-split op below us, then add the extra block too.
424 */
425 node = oldblk->bp->b_addr;
426 if (oldblk->index <= be16_to_cpu(node->hdr.count)) {
427 oldblk->index++;
428 xfs_da_node_add(state, oldblk, addblk);
429 if (useextra) {
430 if (state->extraafter)
431 oldblk->index++;
432 xfs_da_node_add(state, oldblk, &state->extrablk);
433 state->extravalid = 0;
434 }
435 } else {
436 newblk->index++;
437 xfs_da_node_add(state, newblk, addblk);
438 if (useextra) {
439 if (state->extraafter)
440 newblk->index++;
441 xfs_da_node_add(state, newblk, &state->extrablk);
442 state->extravalid = 0;
443 }
444 }
445
446 return(0);
447 }
448
449 /*
450 * Balance the btree elements between two intermediate nodes,
451 * usually one full and one empty.
452 *
453 * NOTE: if blk2 is empty, then it will get the upper half of blk1.
454 */
455 STATIC void
456 xfs_da_node_rebalance(xfs_da_state_t *state, xfs_da_state_blk_t *blk1,
457 xfs_da_state_blk_t *blk2)
458 {
459 xfs_da_intnode_t *node1, *node2, *tmpnode;
460 xfs_da_node_entry_t *btree_s, *btree_d;
461 int count, tmp;
462 xfs_trans_t *tp;
463
464 trace_xfs_da_node_rebalance(state->args);
465
466 node1 = blk1->bp->b_addr;
467 node2 = blk2->bp->b_addr;
468 /*
469 * Figure out how many entries need to move, and in which direction.
470 * Swap the nodes around if that makes it simpler.
471 */
472 if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
473 ((be32_to_cpu(node2->btree[0].hashval) < be32_to_cpu(node1->btree[0].hashval)) ||
474 (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
475 be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
476 tmpnode = node1;
477 node1 = node2;
478 node2 = tmpnode;
479 }
480 ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
481 ASSERT(node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
482 count = (be16_to_cpu(node1->hdr.count) - be16_to_cpu(node2->hdr.count)) / 2;
483 if (count == 0)
484 return;
485 tp = state->args->trans;
486 /*
487 * Two cases: high-to-low and low-to-high.
488 */
489 if (count > 0) {
490 /*
491 * Move elements in node2 up to make a hole.
492 */
493 if ((tmp = be16_to_cpu(node2->hdr.count)) > 0) {
494 tmp *= (uint)sizeof(xfs_da_node_entry_t);
495 btree_s = &node2->btree[0];
496 btree_d = &node2->btree[count];
497 memmove(btree_d, btree_s, tmp);
498 }
499
500 /*
501 * Move the req'd B-tree elements from high in node1 to
502 * low in node2.
503 */
504 be16_add_cpu(&node2->hdr.count, count);
505 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
506 btree_s = &node1->btree[be16_to_cpu(node1->hdr.count) - count];
507 btree_d = &node2->btree[0];
508 memcpy(btree_d, btree_s, tmp);
509 be16_add_cpu(&node1->hdr.count, -count);
510 } else {
511 /*
512 * Move the req'd B-tree elements from low in node2 to
513 * high in node1.
514 */
515 count = -count;
516 tmp = count * (uint)sizeof(xfs_da_node_entry_t);
517 btree_s = &node2->btree[0];
518 btree_d = &node1->btree[be16_to_cpu(node1->hdr.count)];
519 memcpy(btree_d, btree_s, tmp);
520 be16_add_cpu(&node1->hdr.count, count);
521 xfs_trans_log_buf(tp, blk1->bp,
522 XFS_DA_LOGRANGE(node1, btree_d, tmp));
523
524 /*
525 * Move elements in node2 down to fill the hole.
526 */
527 tmp = be16_to_cpu(node2->hdr.count) - count;
528 tmp *= (uint)sizeof(xfs_da_node_entry_t);
529 btree_s = &node2->btree[count];
530 btree_d = &node2->btree[0];
531 memmove(btree_d, btree_s, tmp);
532 be16_add_cpu(&node2->hdr.count, -count);
533 }
534
535 /*
536 * Log header of node 1 and all current bits of node 2.
537 */
538 xfs_trans_log_buf(tp, blk1->bp,
539 XFS_DA_LOGRANGE(node1, &node1->hdr, sizeof(node1->hdr)));
540 xfs_trans_log_buf(tp, blk2->bp,
541 XFS_DA_LOGRANGE(node2, &node2->hdr,
542 sizeof(node2->hdr) +
543 sizeof(node2->btree[0]) * be16_to_cpu(node2->hdr.count)));
544
545 /*
546 * Record the last hashval from each block for upward propagation.
547 * (note: don't use the swapped node pointers)
548 */
549 node1 = blk1->bp->b_addr;
550 node2 = blk2->bp->b_addr;
551 blk1->hashval = be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval);
552 blk2->hashval = be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval);
553
554 /*
555 * Adjust the expected index for insertion.
556 */
557 if (blk1->index >= be16_to_cpu(node1->hdr.count)) {
558 blk2->index = blk1->index - be16_to_cpu(node1->hdr.count);
559 blk1->index = be16_to_cpu(node1->hdr.count) + 1; /* make it invalid */
560 }
561 }
562
563 /*
564 * Add a new entry to an intermediate node.
565 */
566 STATIC void
567 xfs_da_node_add(xfs_da_state_t *state, xfs_da_state_blk_t *oldblk,
568 xfs_da_state_blk_t *newblk)
569 {
570 xfs_da_intnode_t *node;
571 xfs_da_node_entry_t *btree;
572 int tmp;
573
574 trace_xfs_da_node_add(state->args);
575
576 node = oldblk->bp->b_addr;
577 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
578 ASSERT((oldblk->index >= 0) && (oldblk->index <= be16_to_cpu(node->hdr.count)));
579 ASSERT(newblk->blkno != 0);
580 if (state->args->whichfork == XFS_DATA_FORK)
581 ASSERT(newblk->blkno >= state->mp->m_dirleafblk &&
582 newblk->blkno < state->mp->m_dirfreeblk);
583
584 /*
585 * We may need to make some room before we insert the new node.
586 */
587 tmp = 0;
588 btree = &node->btree[ oldblk->index ];
589 if (oldblk->index < be16_to_cpu(node->hdr.count)) {
590 tmp = (be16_to_cpu(node->hdr.count) - oldblk->index) * (uint)sizeof(*btree);
591 memmove(btree + 1, btree, tmp);
592 }
593 btree->hashval = cpu_to_be32(newblk->hashval);
594 btree->before = cpu_to_be32(newblk->blkno);
595 xfs_trans_log_buf(state->args->trans, oldblk->bp,
596 XFS_DA_LOGRANGE(node, btree, tmp + sizeof(*btree)));
597 be16_add_cpu(&node->hdr.count, 1);
598 xfs_trans_log_buf(state->args->trans, oldblk->bp,
599 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
600
601 /*
602 * Copy the last hash value from the oldblk to propagate upwards.
603 */
604 oldblk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1 ].hashval);
605 }
606
607 /*========================================================================
608 * Routines used for shrinking the Btree.
609 *========================================================================*/
610
611 /*
612 * Deallocate an empty leaf node, remove it from its parent,
613 * possibly deallocating that block, etc...
614 */
615 int
616 xfs_da_join(xfs_da_state_t *state)
617 {
618 xfs_da_state_blk_t *drop_blk, *save_blk;
619 int action, error;
620
621 trace_xfs_da_join(state->args);
622
623 action = 0;
624 drop_blk = &state->path.blk[ state->path.active-1 ];
625 save_blk = &state->altpath.blk[ state->path.active-1 ];
626 ASSERT(state->path.blk[0].magic == XFS_DA_NODE_MAGIC);
627 ASSERT(drop_blk->magic == XFS_ATTR_LEAF_MAGIC ||
628 drop_blk->magic == XFS_DIR2_LEAFN_MAGIC);
629
630 /*
631 * Walk back up the tree joining/deallocating as necessary.
632 * When we stop dropping blocks, break out.
633 */
634 for ( ; state->path.active >= 2; drop_blk--, save_blk--,
635 state->path.active--) {
636 /*
637 * See if we can combine the block with a neighbor.
638 * (action == 0) => no options, just leave
639 * (action == 1) => coalesce, then unlink
640 * (action == 2) => block empty, unlink it
641 */
642 switch (drop_blk->magic) {
643 case XFS_ATTR_LEAF_MAGIC:
644 error = xfs_attr_leaf_toosmall(state, &action);
645 if (error)
646 return(error);
647 if (action == 0)
648 return(0);
649 xfs_attr_leaf_unbalance(state, drop_blk, save_blk);
650 break;
651 case XFS_DIR2_LEAFN_MAGIC:
652 error = xfs_dir2_leafn_toosmall(state, &action);
653 if (error)
654 return error;
655 if (action == 0)
656 return 0;
657 xfs_dir2_leafn_unbalance(state, drop_blk, save_blk);
658 break;
659 case XFS_DA_NODE_MAGIC:
660 /*
661 * Remove the offending node, fixup hashvals,
662 * check for a toosmall neighbor.
663 */
664 xfs_da_node_remove(state, drop_blk);
665 xfs_da_fixhashpath(state, &state->path);
666 error = xfs_da_node_toosmall(state, &action);
667 if (error)
668 return(error);
669 if (action == 0)
670 return 0;
671 xfs_da_node_unbalance(state, drop_blk, save_blk);
672 break;
673 }
674 xfs_da_fixhashpath(state, &state->altpath);
675 error = xfs_da_blk_unlink(state, drop_blk, save_blk);
676 xfs_da_state_kill_altpath(state);
677 if (error)
678 return(error);
679 error = xfs_da_shrink_inode(state->args, drop_blk->blkno,
680 drop_blk->bp);
681 drop_blk->bp = NULL;
682 if (error)
683 return(error);
684 }
685 /*
686 * We joined all the way to the top. If it turns out that
687 * we only have one entry in the root, make the child block
688 * the new root.
689 */
690 xfs_da_node_remove(state, drop_blk);
691 xfs_da_fixhashpath(state, &state->path);
692 error = xfs_da_root_join(state, &state->path.blk[0]);
693 return(error);
694 }
695
696 #ifdef DEBUG
697 static void
698 xfs_da_blkinfo_onlychild_validate(struct xfs_da_blkinfo *blkinfo, __u16 level)
699 {
700 __be16 magic = blkinfo->magic;
701
702 if (level == 1) {
703 ASSERT(magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
704 magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
705 } else
706 ASSERT(magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
707 ASSERT(!blkinfo->forw);
708 ASSERT(!blkinfo->back);
709 }
710 #else /* !DEBUG */
711 #define xfs_da_blkinfo_onlychild_validate(blkinfo, level)
712 #endif /* !DEBUG */
713
714 /*
715 * We have only one entry in the root. Copy the only remaining child of
716 * the old root to block 0 as the new root node.
717 */
718 STATIC int
719 xfs_da_root_join(xfs_da_state_t *state, xfs_da_state_blk_t *root_blk)
720 {
721 xfs_da_intnode_t *oldroot;
722 xfs_da_args_t *args;
723 xfs_dablk_t child;
724 struct xfs_buf *bp;
725 int error;
726
727 trace_xfs_da_root_join(state->args);
728
729 args = state->args;
730 ASSERT(args != NULL);
731 ASSERT(root_blk->magic == XFS_DA_NODE_MAGIC);
732 oldroot = root_blk->bp->b_addr;
733 ASSERT(oldroot->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
734 ASSERT(!oldroot->hdr.info.forw);
735 ASSERT(!oldroot->hdr.info.back);
736
737 /*
738 * If the root has more than one child, then don't do anything.
739 */
740 if (be16_to_cpu(oldroot->hdr.count) > 1)
741 return(0);
742
743 /*
744 * Read in the (only) child block, then copy those bytes into
745 * the root block's buffer and free the original child block.
746 */
747 child = be32_to_cpu(oldroot->btree[0].before);
748 ASSERT(child != 0);
749 error = xfs_da_read_buf(args->trans, args->dp, child, -1, &bp,
750 args->whichfork);
751 if (error)
752 return(error);
753 ASSERT(bp != NULL);
754 xfs_da_blkinfo_onlychild_validate(bp->b_addr,
755 be16_to_cpu(oldroot->hdr.level));
756
757 memcpy(root_blk->bp->b_addr, bp->b_addr, state->blocksize);
758 xfs_trans_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
759 error = xfs_da_shrink_inode(args, child, bp);
760 return(error);
761 }
762
763 /*
764 * Check a node block and its neighbors to see if the block should be
765 * collapsed into one or the other neighbor. Always keep the block
766 * with the smaller block number.
767 * If the current block is over 50% full, don't try to join it, return 0.
768 * If the block is empty, fill in the state structure and return 2.
769 * If it can be collapsed, fill in the state structure and return 1.
770 * If nothing can be done, return 0.
771 */
772 STATIC int
773 xfs_da_node_toosmall(xfs_da_state_t *state, int *action)
774 {
775 xfs_da_intnode_t *node;
776 xfs_da_state_blk_t *blk;
777 xfs_da_blkinfo_t *info;
778 int count, forward, error, retval, i;
779 xfs_dablk_t blkno;
780 struct xfs_buf *bp;
781
782 /*
783 * Check for the degenerate case of the block being over 50% full.
784 * If so, it's not worth even looking to see if we might be able
785 * to coalesce with a sibling.
786 */
787 blk = &state->path.blk[ state->path.active-1 ];
788 info = blk->bp->b_addr;
789 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
790 node = (xfs_da_intnode_t *)info;
791 count = be16_to_cpu(node->hdr.count);
792 if (count > (state->node_ents >> 1)) {
793 *action = 0; /* blk over 50%, don't try to join */
794 return(0); /* blk over 50%, don't try to join */
795 }
796
797 /*
798 * Check for the degenerate case of the block being empty.
799 * If the block is empty, we'll simply delete it, no need to
800 * coalesce it with a sibling block. We choose (arbitrarily)
801 * to merge with the forward block unless it is NULL.
802 */
803 if (count == 0) {
804 /*
805 * Make altpath point to the block we want to keep and
806 * path point to the block we want to drop (this one).
807 */
808 forward = (info->forw != 0);
809 memcpy(&state->altpath, &state->path, sizeof(state->path));
810 error = xfs_da_path_shift(state, &state->altpath, forward,
811 0, &retval);
812 if (error)
813 return(error);
814 if (retval) {
815 *action = 0;
816 } else {
817 *action = 2;
818 }
819 return(0);
820 }
821
822 /*
823 * Examine each sibling block to see if we can coalesce with
824 * at least 25% free space to spare. We need to figure out
825 * whether to merge with the forward or the backward block.
826 * We prefer coalescing with the lower numbered sibling so as
827 * to shrink a directory over time.
828 */
829 /* start with smaller blk num */
830 forward = (be32_to_cpu(info->forw) < be32_to_cpu(info->back));
831 for (i = 0; i < 2; forward = !forward, i++) {
832 if (forward)
833 blkno = be32_to_cpu(info->forw);
834 else
835 blkno = be32_to_cpu(info->back);
836 if (blkno == 0)
837 continue;
838 error = xfs_da_read_buf(state->args->trans, state->args->dp,
839 blkno, -1, &bp, state->args->whichfork);
840 if (error)
841 return(error);
842 ASSERT(bp != NULL);
843
844 node = (xfs_da_intnode_t *)info;
845 count = state->node_ents;
846 count -= state->node_ents >> 2;
847 count -= be16_to_cpu(node->hdr.count);
848 node = bp->b_addr;
849 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
850 count -= be16_to_cpu(node->hdr.count);
851 xfs_trans_brelse(state->args->trans, bp);
852 if (count >= 0)
853 break; /* fits with at least 25% to spare */
854 }
855 if (i >= 2) {
856 *action = 0;
857 return(0);
858 }
859
860 /*
861 * Make altpath point to the block we want to keep (the lower
862 * numbered block) and path point to the block we want to drop.
863 */
864 memcpy(&state->altpath, &state->path, sizeof(state->path));
865 if (blkno < blk->blkno) {
866 error = xfs_da_path_shift(state, &state->altpath, forward,
867 0, &retval);
868 if (error) {
869 return(error);
870 }
871 if (retval) {
872 *action = 0;
873 return(0);
874 }
875 } else {
876 error = xfs_da_path_shift(state, &state->path, forward,
877 0, &retval);
878 if (error) {
879 return(error);
880 }
881 if (retval) {
882 *action = 0;
883 return(0);
884 }
885 }
886 *action = 1;
887 return(0);
888 }
889
890 /*
891 * Walk back up the tree adjusting hash values as necessary,
892 * when we stop making changes, return.
893 */
894 void
895 xfs_da_fixhashpath(xfs_da_state_t *state, xfs_da_state_path_t *path)
896 {
897 xfs_da_state_blk_t *blk;
898 xfs_da_intnode_t *node;
899 xfs_da_node_entry_t *btree;
900 xfs_dahash_t lasthash=0;
901 int level, count;
902
903 level = path->active-1;
904 blk = &path->blk[ level ];
905 switch (blk->magic) {
906 case XFS_ATTR_LEAF_MAGIC:
907 lasthash = xfs_attr_leaf_lasthash(blk->bp, &count);
908 if (count == 0)
909 return;
910 break;
911 case XFS_DIR2_LEAFN_MAGIC:
912 lasthash = xfs_dir2_leafn_lasthash(blk->bp, &count);
913 if (count == 0)
914 return;
915 break;
916 case XFS_DA_NODE_MAGIC:
917 lasthash = xfs_da_node_lasthash(blk->bp, &count);
918 if (count == 0)
919 return;
920 break;
921 }
922 for (blk--, level--; level >= 0; blk--, level--) {
923 node = blk->bp->b_addr;
924 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
925 btree = &node->btree[ blk->index ];
926 if (be32_to_cpu(btree->hashval) == lasthash)
927 break;
928 blk->hashval = lasthash;
929 btree->hashval = cpu_to_be32(lasthash);
930 xfs_trans_log_buf(state->args->trans, blk->bp,
931 XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
932
933 lasthash = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
934 }
935 }
936
937 /*
938 * Remove an entry from an intermediate node.
939 */
940 STATIC void
941 xfs_da_node_remove(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk)
942 {
943 xfs_da_intnode_t *node;
944 xfs_da_node_entry_t *btree;
945 int tmp;
946
947 trace_xfs_da_node_remove(state->args);
948
949 node = drop_blk->bp->b_addr;
950 ASSERT(drop_blk->index < be16_to_cpu(node->hdr.count));
951 ASSERT(drop_blk->index >= 0);
952
953 /*
954 * Copy over the offending entry, or just zero it out.
955 */
956 btree = &node->btree[drop_blk->index];
957 if (drop_blk->index < (be16_to_cpu(node->hdr.count)-1)) {
958 tmp = be16_to_cpu(node->hdr.count) - drop_blk->index - 1;
959 tmp *= (uint)sizeof(xfs_da_node_entry_t);
960 memmove(btree, btree + 1, tmp);
961 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
962 XFS_DA_LOGRANGE(node, btree, tmp));
963 btree = &node->btree[be16_to_cpu(node->hdr.count)-1];
964 }
965 memset((char *)btree, 0, sizeof(xfs_da_node_entry_t));
966 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
967 XFS_DA_LOGRANGE(node, btree, sizeof(*btree)));
968 be16_add_cpu(&node->hdr.count, -1);
969 xfs_trans_log_buf(state->args->trans, drop_blk->bp,
970 XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
971
972 /*
973 * Copy the last hash value from the block to propagate upwards.
974 */
975 btree--;
976 drop_blk->hashval = be32_to_cpu(btree->hashval);
977 }
978
979 /*
980 * Unbalance the btree elements between two intermediate nodes,
981 * move all Btree elements from one node into another.
982 */
983 STATIC void
984 xfs_da_node_unbalance(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
985 xfs_da_state_blk_t *save_blk)
986 {
987 xfs_da_intnode_t *drop_node, *save_node;
988 xfs_da_node_entry_t *btree;
989 int tmp;
990 xfs_trans_t *tp;
991
992 trace_xfs_da_node_unbalance(state->args);
993
994 drop_node = drop_blk->bp->b_addr;
995 save_node = save_blk->bp->b_addr;
996 ASSERT(drop_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
997 ASSERT(save_node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
998 tp = state->args->trans;
999
1000 /*
1001 * If the dying block has lower hashvals, then move all the
1002 * elements in the remaining block up to make a hole.
1003 */
1004 if ((be32_to_cpu(drop_node->btree[0].hashval) < be32_to_cpu(save_node->btree[ 0 ].hashval)) ||
1005 (be32_to_cpu(drop_node->btree[be16_to_cpu(drop_node->hdr.count)-1].hashval) <
1006 be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval)))
1007 {
1008 btree = &save_node->btree[be16_to_cpu(drop_node->hdr.count)];
1009 tmp = be16_to_cpu(save_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1010 memmove(btree, &save_node->btree[0], tmp);
1011 btree = &save_node->btree[0];
1012 xfs_trans_log_buf(tp, save_blk->bp,
1013 XFS_DA_LOGRANGE(save_node, btree,
1014 (be16_to_cpu(save_node->hdr.count) + be16_to_cpu(drop_node->hdr.count)) *
1015 sizeof(xfs_da_node_entry_t)));
1016 } else {
1017 btree = &save_node->btree[be16_to_cpu(save_node->hdr.count)];
1018 xfs_trans_log_buf(tp, save_blk->bp,
1019 XFS_DA_LOGRANGE(save_node, btree,
1020 be16_to_cpu(drop_node->hdr.count) *
1021 sizeof(xfs_da_node_entry_t)));
1022 }
1023
1024 /*
1025 * Move all the B-tree elements from drop_blk to save_blk.
1026 */
1027 tmp = be16_to_cpu(drop_node->hdr.count) * (uint)sizeof(xfs_da_node_entry_t);
1028 memcpy(btree, &drop_node->btree[0], tmp);
1029 be16_add_cpu(&save_node->hdr.count, be16_to_cpu(drop_node->hdr.count));
1030
1031 xfs_trans_log_buf(tp, save_blk->bp,
1032 XFS_DA_LOGRANGE(save_node, &save_node->hdr,
1033 sizeof(save_node->hdr)));
1034
1035 /*
1036 * Save the last hashval in the remaining block for upward propagation.
1037 */
1038 save_blk->hashval = be32_to_cpu(save_node->btree[be16_to_cpu(save_node->hdr.count)-1].hashval);
1039 }
1040
1041 /*========================================================================
1042 * Routines used for finding things in the Btree.
1043 *========================================================================*/
1044
1045 /*
1046 * Walk down the Btree looking for a particular filename, filling
1047 * in the state structure as we go.
1048 *
1049 * We will set the state structure to point to each of the elements
1050 * in each of the nodes where either the hashval is or should be.
1051 *
1052 * We support duplicate hashval's so for each entry in the current
1053 * node that could contain the desired hashval, descend. This is a
1054 * pruned depth-first tree search.
1055 */
1056 int /* error */
1057 xfs_da_node_lookup_int(xfs_da_state_t *state, int *result)
1058 {
1059 xfs_da_state_blk_t *blk;
1060 xfs_da_blkinfo_t *curr;
1061 xfs_da_intnode_t *node;
1062 xfs_da_node_entry_t *btree;
1063 xfs_dablk_t blkno;
1064 int probe, span, max, error, retval;
1065 xfs_dahash_t hashval, btreehashval;
1066 xfs_da_args_t *args;
1067
1068 args = state->args;
1069
1070 /*
1071 * Descend thru the B-tree searching each level for the right
1072 * node to use, until the right hashval is found.
1073 */
1074 blkno = (args->whichfork == XFS_DATA_FORK)? state->mp->m_dirleafblk : 0;
1075 for (blk = &state->path.blk[0], state->path.active = 1;
1076 state->path.active <= XFS_DA_NODE_MAXDEPTH;
1077 blk++, state->path.active++) {
1078 /*
1079 * Read the next node down in the tree.
1080 */
1081 blk->blkno = blkno;
1082 error = xfs_da_read_buf(args->trans, args->dp, blkno,
1083 -1, &blk->bp, args->whichfork);
1084 if (error) {
1085 blk->blkno = 0;
1086 state->path.active--;
1087 return(error);
1088 }
1089 curr = blk->bp->b_addr;
1090 blk->magic = be16_to_cpu(curr->magic);
1091 ASSERT(blk->magic == XFS_DA_NODE_MAGIC ||
1092 blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1093 blk->magic == XFS_ATTR_LEAF_MAGIC);
1094
1095 /*
1096 * Search an intermediate node for a match.
1097 */
1098 if (blk->magic == XFS_DA_NODE_MAGIC) {
1099 node = blk->bp->b_addr;
1100 max = be16_to_cpu(node->hdr.count);
1101 blk->hashval = be32_to_cpu(node->btree[max-1].hashval);
1102
1103 /*
1104 * Binary search. (note: small blocks will skip loop)
1105 */
1106 probe = span = max / 2;
1107 hashval = args->hashval;
1108 for (btree = &node->btree[probe]; span > 4;
1109 btree = &node->btree[probe]) {
1110 span /= 2;
1111 btreehashval = be32_to_cpu(btree->hashval);
1112 if (btreehashval < hashval)
1113 probe += span;
1114 else if (btreehashval > hashval)
1115 probe -= span;
1116 else
1117 break;
1118 }
1119 ASSERT((probe >= 0) && (probe < max));
1120 ASSERT((span <= 4) || (be32_to_cpu(btree->hashval) == hashval));
1121
1122 /*
1123 * Since we may have duplicate hashval's, find the first
1124 * matching hashval in the node.
1125 */
1126 while ((probe > 0) && (be32_to_cpu(btree->hashval) >= hashval)) {
1127 btree--;
1128 probe--;
1129 }
1130 while ((probe < max) && (be32_to_cpu(btree->hashval) < hashval)) {
1131 btree++;
1132 probe++;
1133 }
1134
1135 /*
1136 * Pick the right block to descend on.
1137 */
1138 if (probe == max) {
1139 blk->index = max-1;
1140 blkno = be32_to_cpu(node->btree[max-1].before);
1141 } else {
1142 blk->index = probe;
1143 blkno = be32_to_cpu(btree->before);
1144 }
1145 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1146 blk->hashval = xfs_attr_leaf_lasthash(blk->bp, NULL);
1147 break;
1148 } else if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1149 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp, NULL);
1150 break;
1151 }
1152 }
1153
1154 /*
1155 * A leaf block that ends in the hashval that we are interested in
1156 * (final hashval == search hashval) means that the next block may
1157 * contain more entries with the same hashval, shift upward to the
1158 * next leaf and keep searching.
1159 */
1160 for (;;) {
1161 if (blk->magic == XFS_DIR2_LEAFN_MAGIC) {
1162 retval = xfs_dir2_leafn_lookup_int(blk->bp, args,
1163 &blk->index, state);
1164 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1165 retval = xfs_attr_leaf_lookup_int(blk->bp, args);
1166 blk->index = args->index;
1167 args->blkno = blk->blkno;
1168 } else {
1169 ASSERT(0);
1170 return XFS_ERROR(EFSCORRUPTED);
1171 }
1172 if (((retval == ENOENT) || (retval == ENOATTR)) &&
1173 (blk->hashval == args->hashval)) {
1174 error = xfs_da_path_shift(state, &state->path, 1, 1,
1175 &retval);
1176 if (error)
1177 return(error);
1178 if (retval == 0) {
1179 continue;
1180 } else if (blk->magic == XFS_ATTR_LEAF_MAGIC) {
1181 /* path_shift() gives ENOENT */
1182 retval = XFS_ERROR(ENOATTR);
1183 }
1184 }
1185 break;
1186 }
1187 *result = retval;
1188 return(0);
1189 }
1190
1191 /*========================================================================
1192 * Utility routines.
1193 *========================================================================*/
1194
1195 /*
1196 * Link a new block into a doubly linked list of blocks (of whatever type).
1197 */
1198 int /* error */
1199 xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
1200 xfs_da_state_blk_t *new_blk)
1201 {
1202 xfs_da_blkinfo_t *old_info, *new_info, *tmp_info;
1203 xfs_da_args_t *args;
1204 int before=0, error;
1205 struct xfs_buf *bp;
1206
1207 /*
1208 * Set up environment.
1209 */
1210 args = state->args;
1211 ASSERT(args != NULL);
1212 old_info = old_blk->bp->b_addr;
1213 new_info = new_blk->bp->b_addr;
1214 ASSERT(old_blk->magic == XFS_DA_NODE_MAGIC ||
1215 old_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1216 old_blk->magic == XFS_ATTR_LEAF_MAGIC);
1217 ASSERT(old_blk->magic == be16_to_cpu(old_info->magic));
1218 ASSERT(new_blk->magic == be16_to_cpu(new_info->magic));
1219 ASSERT(old_blk->magic == new_blk->magic);
1220
1221 switch (old_blk->magic) {
1222 case XFS_ATTR_LEAF_MAGIC:
1223 before = xfs_attr_leaf_order(old_blk->bp, new_blk->bp);
1224 break;
1225 case XFS_DIR2_LEAFN_MAGIC:
1226 before = xfs_dir2_leafn_order(old_blk->bp, new_blk->bp);
1227 break;
1228 case XFS_DA_NODE_MAGIC:
1229 before = xfs_da_node_order(old_blk->bp, new_blk->bp);
1230 break;
1231 }
1232
1233 /*
1234 * Link blocks in appropriate order.
1235 */
1236 if (before) {
1237 /*
1238 * Link new block in before existing block.
1239 */
1240 trace_xfs_da_link_before(args);
1241 new_info->forw = cpu_to_be32(old_blk->blkno);
1242 new_info->back = old_info->back;
1243 if (old_info->back) {
1244 error = xfs_da_read_buf(args->trans, args->dp,
1245 be32_to_cpu(old_info->back),
1246 -1, &bp, args->whichfork);
1247 if (error)
1248 return(error);
1249 ASSERT(bp != NULL);
1250 tmp_info = bp->b_addr;
1251 ASSERT(be16_to_cpu(tmp_info->magic) == be16_to_cpu(old_info->magic));
1252 ASSERT(be32_to_cpu(tmp_info->forw) == old_blk->blkno);
1253 tmp_info->forw = cpu_to_be32(new_blk->blkno);
1254 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1255 }
1256 old_info->back = cpu_to_be32(new_blk->blkno);
1257 } else {
1258 /*
1259 * Link new block in after existing block.
1260 */
1261 trace_xfs_da_link_after(args);
1262 new_info->forw = old_info->forw;
1263 new_info->back = cpu_to_be32(old_blk->blkno);
1264 if (old_info->forw) {
1265 error = xfs_da_read_buf(args->trans, args->dp,
1266 be32_to_cpu(old_info->forw),
1267 -1, &bp, args->whichfork);
1268 if (error)
1269 return(error);
1270 ASSERT(bp != NULL);
1271 tmp_info = bp->b_addr;
1272 ASSERT(tmp_info->magic == old_info->magic);
1273 ASSERT(be32_to_cpu(tmp_info->back) == old_blk->blkno);
1274 tmp_info->back = cpu_to_be32(new_blk->blkno);
1275 xfs_trans_log_buf(args->trans, bp, 0, sizeof(*tmp_info)-1);
1276 }
1277 old_info->forw = cpu_to_be32(new_blk->blkno);
1278 }
1279
1280 xfs_trans_log_buf(args->trans, old_blk->bp, 0, sizeof(*tmp_info) - 1);
1281 xfs_trans_log_buf(args->trans, new_blk->bp, 0, sizeof(*tmp_info) - 1);
1282 return(0);
1283 }
1284
1285 /*
1286 * Compare two intermediate nodes for "order".
1287 */
1288 STATIC int
1289 xfs_da_node_order(
1290 struct xfs_buf *node1_bp,
1291 struct xfs_buf *node2_bp)
1292 {
1293 xfs_da_intnode_t *node1, *node2;
1294
1295 node1 = node1_bp->b_addr;
1296 node2 = node2_bp->b_addr;
1297 ASSERT(node1->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC) &&
1298 node2->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1299 if ((be16_to_cpu(node1->hdr.count) > 0) && (be16_to_cpu(node2->hdr.count) > 0) &&
1300 ((be32_to_cpu(node2->btree[0].hashval) <
1301 be32_to_cpu(node1->btree[0].hashval)) ||
1302 (be32_to_cpu(node2->btree[be16_to_cpu(node2->hdr.count)-1].hashval) <
1303 be32_to_cpu(node1->btree[be16_to_cpu(node1->hdr.count)-1].hashval)))) {
1304 return(1);
1305 }
1306 return(0);
1307 }
1308
1309 /*
1310 * Pick up the last hashvalue from an intermediate node.
1311 */
1312 STATIC uint
1313 xfs_da_node_lasthash(
1314 struct xfs_buf *bp,
1315 int *count)
1316 {
1317 xfs_da_intnode_t *node;
1318
1319 node = bp->b_addr;
1320 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1321 if (count)
1322 *count = be16_to_cpu(node->hdr.count);
1323 if (!node->hdr.count)
1324 return(0);
1325 return be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1326 }
1327
1328 /*
1329 * Unlink a block from a doubly linked list of blocks.
1330 */
1331 STATIC int /* error */
1332 xfs_da_blk_unlink(xfs_da_state_t *state, xfs_da_state_blk_t *drop_blk,
1333 xfs_da_state_blk_t *save_blk)
1334 {
1335 xfs_da_blkinfo_t *drop_info, *save_info, *tmp_info;
1336 xfs_da_args_t *args;
1337 struct xfs_buf *bp;
1338 int error;
1339
1340 /*
1341 * Set up environment.
1342 */
1343 args = state->args;
1344 ASSERT(args != NULL);
1345 save_info = save_blk->bp->b_addr;
1346 drop_info = drop_blk->bp->b_addr;
1347 ASSERT(save_blk->magic == XFS_DA_NODE_MAGIC ||
1348 save_blk->magic == XFS_DIR2_LEAFN_MAGIC ||
1349 save_blk->magic == XFS_ATTR_LEAF_MAGIC);
1350 ASSERT(save_blk->magic == be16_to_cpu(save_info->magic));
1351 ASSERT(drop_blk->magic == be16_to_cpu(drop_info->magic));
1352 ASSERT(save_blk->magic == drop_blk->magic);
1353 ASSERT((be32_to_cpu(save_info->forw) == drop_blk->blkno) ||
1354 (be32_to_cpu(save_info->back) == drop_blk->blkno));
1355 ASSERT((be32_to_cpu(drop_info->forw) == save_blk->blkno) ||
1356 (be32_to_cpu(drop_info->back) == save_blk->blkno));
1357
1358 /*
1359 * Unlink the leaf block from the doubly linked chain of leaves.
1360 */
1361 if (be32_to_cpu(save_info->back) == drop_blk->blkno) {
1362 trace_xfs_da_unlink_back(args);
1363 save_info->back = drop_info->back;
1364 if (drop_info->back) {
1365 error = xfs_da_read_buf(args->trans, args->dp,
1366 be32_to_cpu(drop_info->back),
1367 -1, &bp, args->whichfork);
1368 if (error)
1369 return(error);
1370 ASSERT(bp != NULL);
1371 tmp_info = bp->b_addr;
1372 ASSERT(tmp_info->magic == save_info->magic);
1373 ASSERT(be32_to_cpu(tmp_info->forw) == drop_blk->blkno);
1374 tmp_info->forw = cpu_to_be32(save_blk->blkno);
1375 xfs_trans_log_buf(args->trans, bp, 0,
1376 sizeof(*tmp_info) - 1);
1377 }
1378 } else {
1379 trace_xfs_da_unlink_forward(args);
1380 save_info->forw = drop_info->forw;
1381 if (drop_info->forw) {
1382 error = xfs_da_read_buf(args->trans, args->dp,
1383 be32_to_cpu(drop_info->forw),
1384 -1, &bp, args->whichfork);
1385 if (error)
1386 return(error);
1387 ASSERT(bp != NULL);
1388 tmp_info = bp->b_addr;
1389 ASSERT(tmp_info->magic == save_info->magic);
1390 ASSERT(be32_to_cpu(tmp_info->back) == drop_blk->blkno);
1391 tmp_info->back = cpu_to_be32(save_blk->blkno);
1392 xfs_trans_log_buf(args->trans, bp, 0,
1393 sizeof(*tmp_info) - 1);
1394 }
1395 }
1396
1397 xfs_trans_log_buf(args->trans, save_blk->bp, 0, sizeof(*save_info) - 1);
1398 return(0);
1399 }
1400
1401 /*
1402 * Move a path "forward" or "!forward" one block at the current level.
1403 *
1404 * This routine will adjust a "path" to point to the next block
1405 * "forward" (higher hashvalues) or "!forward" (lower hashvals) in the
1406 * Btree, including updating pointers to the intermediate nodes between
1407 * the new bottom and the root.
1408 */
1409 int /* error */
1410 xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
1411 int forward, int release, int *result)
1412 {
1413 xfs_da_state_blk_t *blk;
1414 xfs_da_blkinfo_t *info;
1415 xfs_da_intnode_t *node;
1416 xfs_da_args_t *args;
1417 xfs_dablk_t blkno=0;
1418 int level, error;
1419
1420 /*
1421 * Roll up the Btree looking for the first block where our
1422 * current index is not at the edge of the block. Note that
1423 * we skip the bottom layer because we want the sibling block.
1424 */
1425 args = state->args;
1426 ASSERT(args != NULL);
1427 ASSERT(path != NULL);
1428 ASSERT((path->active > 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
1429 level = (path->active-1) - 1; /* skip bottom layer in path */
1430 for (blk = &path->blk[level]; level >= 0; blk--, level--) {
1431 ASSERT(blk->bp != NULL);
1432 node = blk->bp->b_addr;
1433 ASSERT(node->hdr.info.magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1434 if (forward && (blk->index < be16_to_cpu(node->hdr.count)-1)) {
1435 blk->index++;
1436 blkno = be32_to_cpu(node->btree[blk->index].before);
1437 break;
1438 } else if (!forward && (blk->index > 0)) {
1439 blk->index--;
1440 blkno = be32_to_cpu(node->btree[blk->index].before);
1441 break;
1442 }
1443 }
1444 if (level < 0) {
1445 *result = XFS_ERROR(ENOENT); /* we're out of our tree */
1446 ASSERT(args->op_flags & XFS_DA_OP_OKNOENT);
1447 return(0);
1448 }
1449
1450 /*
1451 * Roll down the edge of the subtree until we reach the
1452 * same depth we were at originally.
1453 */
1454 for (blk++, level++; level < path->active; blk++, level++) {
1455 /*
1456 * Release the old block.
1457 * (if it's dirty, trans won't actually let go)
1458 */
1459 if (release)
1460 xfs_trans_brelse(args->trans, blk->bp);
1461
1462 /*
1463 * Read the next child block.
1464 */
1465 blk->blkno = blkno;
1466 error = xfs_da_read_buf(args->trans, args->dp, blkno, -1,
1467 &blk->bp, args->whichfork);
1468 if (error)
1469 return(error);
1470 ASSERT(blk->bp != NULL);
1471 info = blk->bp->b_addr;
1472 ASSERT(info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1473 info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC) ||
1474 info->magic == cpu_to_be16(XFS_ATTR_LEAF_MAGIC));
1475 blk->magic = be16_to_cpu(info->magic);
1476 if (blk->magic == XFS_DA_NODE_MAGIC) {
1477 node = (xfs_da_intnode_t *)info;
1478 blk->hashval = be32_to_cpu(node->btree[be16_to_cpu(node->hdr.count)-1].hashval);
1479 if (forward)
1480 blk->index = 0;
1481 else
1482 blk->index = be16_to_cpu(node->hdr.count)-1;
1483 blkno = be32_to_cpu(node->btree[blk->index].before);
1484 } else {
1485 ASSERT(level == path->active-1);
1486 blk->index = 0;
1487 switch(blk->magic) {
1488 case XFS_ATTR_LEAF_MAGIC:
1489 blk->hashval = xfs_attr_leaf_lasthash(blk->bp,
1490 NULL);
1491 break;
1492 case XFS_DIR2_LEAFN_MAGIC:
1493 blk->hashval = xfs_dir2_leafn_lasthash(blk->bp,
1494 NULL);
1495 break;
1496 default:
1497 ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC ||
1498 blk->magic == XFS_DIR2_LEAFN_MAGIC);
1499 break;
1500 }
1501 }
1502 }
1503 *result = 0;
1504 return(0);
1505 }
1506
1507
1508 /*========================================================================
1509 * Utility routines.
1510 *========================================================================*/
1511
1512 /*
1513 * Implement a simple hash on a character string.
1514 * Rotate the hash value by 7 bits, then XOR each character in.
1515 * This is implemented with some source-level loop unrolling.
1516 */
1517 xfs_dahash_t
1518 xfs_da_hashname(const __uint8_t *name, int namelen)
1519 {
1520 xfs_dahash_t hash;
1521
1522 /*
1523 * Do four characters at a time as long as we can.
1524 */
1525 for (hash = 0; namelen >= 4; namelen -= 4, name += 4)
1526 hash = (name[0] << 21) ^ (name[1] << 14) ^ (name[2] << 7) ^
1527 (name[3] << 0) ^ rol32(hash, 7 * 4);
1528
1529 /*
1530 * Now do the rest of the characters.
1531 */
1532 switch (namelen) {
1533 case 3:
1534 return (name[0] << 14) ^ (name[1] << 7) ^ (name[2] << 0) ^
1535 rol32(hash, 7 * 3);
1536 case 2:
1537 return (name[0] << 7) ^ (name[1] << 0) ^ rol32(hash, 7 * 2);
1538 case 1:
1539 return (name[0] << 0) ^ rol32(hash, 7 * 1);
1540 default: /* case 0: */
1541 return hash;
1542 }
1543 }
1544
1545 enum xfs_dacmp
1546 xfs_da_compname(
1547 struct xfs_da_args *args,
1548 const unsigned char *name,
1549 int len)
1550 {
1551 return (args->namelen == len && memcmp(args->name, name, len) == 0) ?
1552 XFS_CMP_EXACT : XFS_CMP_DIFFERENT;
1553 }
1554
1555 static xfs_dahash_t
1556 xfs_default_hashname(
1557 struct xfs_name *name)
1558 {
1559 return xfs_da_hashname(name->name, name->len);
1560 }
1561
1562 const struct xfs_nameops xfs_default_nameops = {
1563 .hashname = xfs_default_hashname,
1564 .compname = xfs_da_compname
1565 };
1566
1567 int
1568 xfs_da_grow_inode_int(
1569 struct xfs_da_args *args,
1570 xfs_fileoff_t *bno,
1571 int count)
1572 {
1573 struct xfs_trans *tp = args->trans;
1574 struct xfs_inode *dp = args->dp;
1575 int w = args->whichfork;
1576 xfs_drfsbno_t nblks = dp->i_d.di_nblocks;
1577 struct xfs_bmbt_irec map, *mapp;
1578 int nmap, error, got, i, mapi;
1579
1580 /*
1581 * Find a spot in the file space to put the new block.
1582 */
1583 error = xfs_bmap_first_unused(tp, dp, count, bno, w);
1584 if (error)
1585 return error;
1586
1587 /*
1588 * Try mapping it in one filesystem block.
1589 */
1590 nmap = 1;
1591 ASSERT(args->firstblock != NULL);
1592 error = xfs_bmapi_write(tp, dp, *bno, count,
1593 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA|XFS_BMAPI_CONTIG,
1594 args->firstblock, args->total, &map, &nmap,
1595 args->flist);
1596 if (error)
1597 return error;
1598
1599 ASSERT(nmap <= 1);
1600 if (nmap == 1) {
1601 mapp = &map;
1602 mapi = 1;
1603 } else if (nmap == 0 && count > 1) {
1604 xfs_fileoff_t b;
1605 int c;
1606
1607 /*
1608 * If we didn't get it and the block might work if fragmented,
1609 * try without the CONTIG flag. Loop until we get it all.
1610 */
1611 mapp = kmem_alloc(sizeof(*mapp) * count, KM_SLEEP);
1612 for (b = *bno, mapi = 0; b < *bno + count; ) {
1613 nmap = MIN(XFS_BMAP_MAX_NMAP, count);
1614 c = (int)(*bno + count - b);
1615 error = xfs_bmapi_write(tp, dp, b, c,
1616 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
1617 args->firstblock, args->total,
1618 &mapp[mapi], &nmap, args->flist);
1619 if (error)
1620 goto out_free_map;
1621 if (nmap < 1)
1622 break;
1623 mapi += nmap;
1624 b = mapp[mapi - 1].br_startoff +
1625 mapp[mapi - 1].br_blockcount;
1626 }
1627 } else {
1628 mapi = 0;
1629 mapp = NULL;
1630 }
1631
1632 /*
1633 * Count the blocks we got, make sure it matches the total.
1634 */
1635 for (i = 0, got = 0; i < mapi; i++)
1636 got += mapp[i].br_blockcount;
1637 if (got != count || mapp[0].br_startoff != *bno ||
1638 mapp[mapi - 1].br_startoff + mapp[mapi - 1].br_blockcount !=
1639 *bno + count) {
1640 error = XFS_ERROR(ENOSPC);
1641 goto out_free_map;
1642 }
1643
1644 /* account for newly allocated blocks in reserved blocks total */
1645 args->total -= dp->i_d.di_nblocks - nblks;
1646
1647 out_free_map:
1648 if (mapp != &map)
1649 kmem_free(mapp);
1650 return error;
1651 }
1652
1653 /*
1654 * Add a block to the btree ahead of the file.
1655 * Return the new block number to the caller.
1656 */
1657 int
1658 xfs_da_grow_inode(
1659 struct xfs_da_args *args,
1660 xfs_dablk_t *new_blkno)
1661 {
1662 xfs_fileoff_t bno;
1663 int count;
1664 int error;
1665
1666 trace_xfs_da_grow_inode(args);
1667
1668 if (args->whichfork == XFS_DATA_FORK) {
1669 bno = args->dp->i_mount->m_dirleafblk;
1670 count = args->dp->i_mount->m_dirblkfsbs;
1671 } else {
1672 bno = 0;
1673 count = 1;
1674 }
1675
1676 error = xfs_da_grow_inode_int(args, &bno, count);
1677 if (!error)
1678 *new_blkno = (xfs_dablk_t)bno;
1679 return error;
1680 }
1681
1682 /*
1683 * Ick. We need to always be able to remove a btree block, even
1684 * if there's no space reservation because the filesystem is full.
1685 * This is called if xfs_bunmapi on a btree block fails due to ENOSPC.
1686 * It swaps the target block with the last block in the file. The
1687 * last block in the file can always be removed since it can't cause
1688 * a bmap btree split to do that.
1689 */
1690 STATIC int
1691 xfs_da_swap_lastblock(
1692 xfs_da_args_t *args,
1693 xfs_dablk_t *dead_blknop,
1694 struct xfs_buf **dead_bufp)
1695 {
1696 xfs_dablk_t dead_blkno, last_blkno, sib_blkno, par_blkno;
1697 struct xfs_buf *dead_buf, *last_buf, *sib_buf, *par_buf;
1698 xfs_fileoff_t lastoff;
1699 xfs_inode_t *ip;
1700 xfs_trans_t *tp;
1701 xfs_mount_t *mp;
1702 int error, w, entno, level, dead_level;
1703 xfs_da_blkinfo_t *dead_info, *sib_info;
1704 xfs_da_intnode_t *par_node, *dead_node;
1705 xfs_dir2_leaf_t *dead_leaf2;
1706 xfs_dahash_t dead_hash;
1707
1708 trace_xfs_da_swap_lastblock(args);
1709
1710 dead_buf = *dead_bufp;
1711 dead_blkno = *dead_blknop;
1712 tp = args->trans;
1713 ip = args->dp;
1714 w = args->whichfork;
1715 ASSERT(w == XFS_DATA_FORK);
1716 mp = ip->i_mount;
1717 lastoff = mp->m_dirfreeblk;
1718 error = xfs_bmap_last_before(tp, ip, &lastoff, w);
1719 if (error)
1720 return error;
1721 if (unlikely(lastoff == 0)) {
1722 XFS_ERROR_REPORT("xfs_da_swap_lastblock(1)", XFS_ERRLEVEL_LOW,
1723 mp);
1724 return XFS_ERROR(EFSCORRUPTED);
1725 }
1726 /*
1727 * Read the last block in the btree space.
1728 */
1729 last_blkno = (xfs_dablk_t)lastoff - mp->m_dirblkfsbs;
1730 if ((error = xfs_da_read_buf(tp, ip, last_blkno, -1, &last_buf, w)))
1731 return error;
1732 /*
1733 * Copy the last block into the dead buffer and log it.
1734 */
1735 memcpy(dead_buf->b_addr, last_buf->b_addr, mp->m_dirblksize);
1736 xfs_trans_log_buf(tp, dead_buf, 0, mp->m_dirblksize - 1);
1737 dead_info = dead_buf->b_addr;
1738 /*
1739 * Get values from the moved block.
1740 */
1741 if (dead_info->magic == cpu_to_be16(XFS_DIR2_LEAFN_MAGIC)) {
1742 dead_leaf2 = (xfs_dir2_leaf_t *)dead_info;
1743 dead_level = 0;
1744 dead_hash = be32_to_cpu(dead_leaf2->ents[be16_to_cpu(dead_leaf2->hdr.count) - 1].hashval);
1745 } else {
1746 ASSERT(dead_info->magic == cpu_to_be16(XFS_DA_NODE_MAGIC));
1747 dead_node = (xfs_da_intnode_t *)dead_info;
1748 dead_level = be16_to_cpu(dead_node->hdr.level);
1749 dead_hash = be32_to_cpu(dead_node->btree[be16_to_cpu(dead_node->hdr.count) - 1].hashval);
1750 }
1751 sib_buf = par_buf = NULL;
1752 /*
1753 * If the moved block has a left sibling, fix up the pointers.
1754 */
1755 if ((sib_blkno = be32_to_cpu(dead_info->back))) {
1756 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1757 goto done;
1758 sib_info = sib_buf->b_addr;
1759 if (unlikely(
1760 be32_to_cpu(sib_info->forw) != last_blkno ||
1761 sib_info->magic != dead_info->magic)) {
1762 XFS_ERROR_REPORT("xfs_da_swap_lastblock(2)",
1763 XFS_ERRLEVEL_LOW, mp);
1764 error = XFS_ERROR(EFSCORRUPTED);
1765 goto done;
1766 }
1767 sib_info->forw = cpu_to_be32(dead_blkno);
1768 xfs_trans_log_buf(tp, sib_buf,
1769 XFS_DA_LOGRANGE(sib_info, &sib_info->forw,
1770 sizeof(sib_info->forw)));
1771 sib_buf = NULL;
1772 }
1773 /*
1774 * If the moved block has a right sibling, fix up the pointers.
1775 */
1776 if ((sib_blkno = be32_to_cpu(dead_info->forw))) {
1777 if ((error = xfs_da_read_buf(tp, ip, sib_blkno, -1, &sib_buf, w)))
1778 goto done;
1779 sib_info = sib_buf->b_addr;
1780 if (unlikely(
1781 be32_to_cpu(sib_info->back) != last_blkno ||
1782 sib_info->magic != dead_info->magic)) {
1783 XFS_ERROR_REPORT("xfs_da_swap_lastblock(3)",
1784 XFS_ERRLEVEL_LOW, mp);
1785 error = XFS_ERROR(EFSCORRUPTED);
1786 goto done;
1787 }
1788 sib_info->back = cpu_to_be32(dead_blkno);
1789 xfs_trans_log_buf(tp, sib_buf,
1790 XFS_DA_LOGRANGE(sib_info, &sib_info->back,
1791 sizeof(sib_info->back)));
1792 sib_buf = NULL;
1793 }
1794 par_blkno = mp->m_dirleafblk;
1795 level = -1;
1796 /*
1797 * Walk down the tree looking for the parent of the moved block.
1798 */
1799 for (;;) {
1800 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1801 goto done;
1802 par_node = par_buf->b_addr;
1803 if (unlikely(par_node->hdr.info.magic !=
1804 cpu_to_be16(XFS_DA_NODE_MAGIC) ||
1805 (level >= 0 && level != be16_to_cpu(par_node->hdr.level) + 1))) {
1806 XFS_ERROR_REPORT("xfs_da_swap_lastblock(4)",
1807 XFS_ERRLEVEL_LOW, mp);
1808 error = XFS_ERROR(EFSCORRUPTED);
1809 goto done;
1810 }
1811 level = be16_to_cpu(par_node->hdr.level);
1812 for (entno = 0;
1813 entno < be16_to_cpu(par_node->hdr.count) &&
1814 be32_to_cpu(par_node->btree[entno].hashval) < dead_hash;
1815 entno++)
1816 continue;
1817 if (unlikely(entno == be16_to_cpu(par_node->hdr.count))) {
1818 XFS_ERROR_REPORT("xfs_da_swap_lastblock(5)",
1819 XFS_ERRLEVEL_LOW, mp);
1820 error = XFS_ERROR(EFSCORRUPTED);
1821 goto done;
1822 }
1823 par_blkno = be32_to_cpu(par_node->btree[entno].before);
1824 if (level == dead_level + 1)
1825 break;
1826 xfs_trans_brelse(tp, par_buf);
1827 par_buf = NULL;
1828 }
1829 /*
1830 * We're in the right parent block.
1831 * Look for the right entry.
1832 */
1833 for (;;) {
1834 for (;
1835 entno < be16_to_cpu(par_node->hdr.count) &&
1836 be32_to_cpu(par_node->btree[entno].before) != last_blkno;
1837 entno++)
1838 continue;
1839 if (entno < be16_to_cpu(par_node->hdr.count))
1840 break;
1841 par_blkno = be32_to_cpu(par_node->hdr.info.forw);
1842 xfs_trans_brelse(tp, par_buf);
1843 par_buf = NULL;
1844 if (unlikely(par_blkno == 0)) {
1845 XFS_ERROR_REPORT("xfs_da_swap_lastblock(6)",
1846 XFS_ERRLEVEL_LOW, mp);
1847 error = XFS_ERROR(EFSCORRUPTED);
1848 goto done;
1849 }
1850 if ((error = xfs_da_read_buf(tp, ip, par_blkno, -1, &par_buf, w)))
1851 goto done;
1852 par_node = par_buf->b_addr;
1853 if (unlikely(
1854 be16_to_cpu(par_node->hdr.level) != level ||
1855 par_node->hdr.info.magic != cpu_to_be16(XFS_DA_NODE_MAGIC))) {
1856 XFS_ERROR_REPORT("xfs_da_swap_lastblock(7)",
1857 XFS_ERRLEVEL_LOW, mp);
1858 error = XFS_ERROR(EFSCORRUPTED);
1859 goto done;
1860 }
1861 entno = 0;
1862 }
1863 /*
1864 * Update the parent entry pointing to the moved block.
1865 */
1866 par_node->btree[entno].before = cpu_to_be32(dead_blkno);
1867 xfs_trans_log_buf(tp, par_buf,
1868 XFS_DA_LOGRANGE(par_node, &par_node->btree[entno].before,
1869 sizeof(par_node->btree[entno].before)));
1870 *dead_blknop = last_blkno;
1871 *dead_bufp = last_buf;
1872 return 0;
1873 done:
1874 if (par_buf)
1875 xfs_trans_brelse(tp, par_buf);
1876 if (sib_buf)
1877 xfs_trans_brelse(tp, sib_buf);
1878 xfs_trans_brelse(tp, last_buf);
1879 return error;
1880 }
1881
1882 /*
1883 * Remove a btree block from a directory or attribute.
1884 */
1885 int
1886 xfs_da_shrink_inode(
1887 xfs_da_args_t *args,
1888 xfs_dablk_t dead_blkno,
1889 struct xfs_buf *dead_buf)
1890 {
1891 xfs_inode_t *dp;
1892 int done, error, w, count;
1893 xfs_trans_t *tp;
1894 xfs_mount_t *mp;
1895
1896 trace_xfs_da_shrink_inode(args);
1897
1898 dp = args->dp;
1899 w = args->whichfork;
1900 tp = args->trans;
1901 mp = dp->i_mount;
1902 if (w == XFS_DATA_FORK)
1903 count = mp->m_dirblkfsbs;
1904 else
1905 count = 1;
1906 for (;;) {
1907 /*
1908 * Remove extents. If we get ENOSPC for a dir we have to move
1909 * the last block to the place we want to kill.
1910 */
1911 if ((error = xfs_bunmapi(tp, dp, dead_blkno, count,
1912 xfs_bmapi_aflag(w)|XFS_BMAPI_METADATA,
1913 0, args->firstblock, args->flist,
1914 &done)) == ENOSPC) {
1915 if (w != XFS_DATA_FORK)
1916 break;
1917 if ((error = xfs_da_swap_lastblock(args, &dead_blkno,
1918 &dead_buf)))
1919 break;
1920 } else {
1921 break;
1922 }
1923 }
1924 xfs_trans_binval(tp, dead_buf);
1925 return error;
1926 }
1927
1928 /*
1929 * See if the mapping(s) for this btree block are valid, i.e.
1930 * don't contain holes, are logically contiguous, and cover the whole range.
1931 */
1932 STATIC int
1933 xfs_da_map_covers_blocks(
1934 int nmap,
1935 xfs_bmbt_irec_t *mapp,
1936 xfs_dablk_t bno,
1937 int count)
1938 {
1939 int i;
1940 xfs_fileoff_t off;
1941
1942 for (i = 0, off = bno; i < nmap; i++) {
1943 if (mapp[i].br_startblock == HOLESTARTBLOCK ||
1944 mapp[i].br_startblock == DELAYSTARTBLOCK) {
1945 return 0;
1946 }
1947 if (off != mapp[i].br_startoff) {
1948 return 0;
1949 }
1950 off += mapp[i].br_blockcount;
1951 }
1952 return off == bno + count;
1953 }
1954
1955 /*
1956 * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map.
1957 *
1958 * For the single map case, it is assumed that the caller has provided a pointer
1959 * to a valid xfs_buf_map. For the multiple map case, this function will
1960 * allocate the xfs_buf_map to hold all the maps and replace the caller's single
1961 * map pointer with the allocated map.
1962 */
1963 static int
1964 xfs_buf_map_from_irec(
1965 struct xfs_mount *mp,
1966 struct xfs_buf_map **mapp,
1967 unsigned int *nmaps,
1968 struct xfs_bmbt_irec *irecs,
1969 unsigned int nirecs)
1970 {
1971 struct xfs_buf_map *map;
1972 int i;
1973
1974 ASSERT(*nmaps == 1);
1975 ASSERT(nirecs >= 1);
1976
1977 if (nirecs > 1) {
1978 map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_SLEEP);
1979 if (!map)
1980 return ENOMEM;
1981 *mapp = map;
1982 }
1983
1984 *nmaps = nirecs;
1985 map = *mapp;
1986 for (i = 0; i < *nmaps; i++) {
1987 ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK &&
1988 irecs[i].br_startblock != HOLESTARTBLOCK);
1989 map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock);
1990 map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount);
1991 }
1992 return 0;
1993 }
1994
1995 /*
1996 * Map the block we are given ready for reading. There are three possible return
1997 * values:
1998 * -1 - will be returned if we land in a hole and mappedbno == -2 so the
1999 * caller knows not to execute a subsequent read.
2000 * 0 - if we mapped the block successfully
2001 * >0 - positive error number if there was an error.
2002 */
2003 static int
2004 xfs_dabuf_map(
2005 struct xfs_trans *trans,
2006 struct xfs_inode *dp,
2007 xfs_dablk_t bno,
2008 xfs_daddr_t mappedbno,
2009 int whichfork,
2010 struct xfs_buf_map **map,
2011 int *nmaps)
2012 {
2013 struct xfs_mount *mp = dp->i_mount;
2014 int nfsb;
2015 int error = 0;
2016 struct xfs_bmbt_irec irec;
2017 struct xfs_bmbt_irec *irecs = &irec;
2018 int nirecs;
2019
2020 ASSERT(map && *map);
2021 ASSERT(*nmaps == 1);
2022
2023 nfsb = (whichfork == XFS_DATA_FORK) ? mp->m_dirblkfsbs : 1;
2024
2025 /*
2026 * Caller doesn't have a mapping. -2 means don't complain
2027 * if we land in a hole.
2028 */
2029 if (mappedbno == -1 || mappedbno == -2) {
2030 /*
2031 * Optimize the one-block case.
2032 */
2033 if (nfsb != 1)
2034 irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_SLEEP);
2035
2036 nirecs = nfsb;
2037 error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs,
2038 &nirecs, xfs_bmapi_aflag(whichfork));
2039 if (error)
2040 goto out;
2041 } else {
2042 irecs->br_startblock = XFS_DADDR_TO_FSB(mp, mappedbno);
2043 irecs->br_startoff = (xfs_fileoff_t)bno;
2044 irecs->br_blockcount = nfsb;
2045 irecs->br_state = 0;
2046 nirecs = 1;
2047 }
2048
2049 if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) {
2050 error = mappedbno == -2 ? -1 : XFS_ERROR(EFSCORRUPTED);
2051 if (unlikely(error == EFSCORRUPTED)) {
2052 if (xfs_error_level >= XFS_ERRLEVEL_LOW) {
2053 int i;
2054 xfs_alert(mp, "%s: bno %lld dir: inode %lld",
2055 __func__, (long long)bno,
2056 (long long)dp->i_ino);
2057 for (i = 0; i < *nmaps; i++) {
2058 xfs_alert(mp,
2059 "[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d",
2060 i,
2061 (long long)irecs[i].br_startoff,
2062 (long long)irecs[i].br_startblock,
2063 (long long)irecs[i].br_blockcount,
2064 irecs[i].br_state);
2065 }
2066 }
2067 XFS_ERROR_REPORT("xfs_da_do_buf(1)",
2068 XFS_ERRLEVEL_LOW, mp);
2069 }
2070 goto out;
2071 }
2072 error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs);
2073 out:
2074 if (irecs != &irec)
2075 kmem_free(irecs);
2076 return error;
2077 }
2078
2079 /*
2080 * Get a buffer for the dir/attr block.
2081 */
2082 int
2083 xfs_da_get_buf(
2084 struct xfs_trans *trans,
2085 struct xfs_inode *dp,
2086 xfs_dablk_t bno,
2087 xfs_daddr_t mappedbno,
2088 struct xfs_buf **bpp,
2089 int whichfork)
2090 {
2091 struct xfs_buf *bp;
2092 struct xfs_buf_map map;
2093 struct xfs_buf_map *mapp;
2094 int nmap;
2095 int error;
2096
2097 *bpp = NULL;
2098 mapp = &map;
2099 nmap = 1;
2100 error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
2101 &mapp, &nmap);
2102 if (error) {
2103 /* mapping a hole is not an error, but we don't continue */
2104 if (error == -1)
2105 error = 0;
2106 goto out_free;
2107 }
2108
2109 bp = xfs_trans_get_buf_map(trans, dp->i_mount->m_ddev_targp,
2110 mapp, nmap, 0);
2111 error = bp ? bp->b_error : XFS_ERROR(EIO);
2112 if (error) {
2113 xfs_trans_brelse(trans, bp);
2114 goto out_free;
2115 }
2116
2117 *bpp = bp;
2118
2119 out_free:
2120 if (mapp != &map)
2121 kmem_free(mapp);
2122
2123 return error;
2124 }
2125
2126 /*
2127 * Get a buffer for the dir/attr block, fill in the contents.
2128 */
2129 int
2130 xfs_da_read_buf(
2131 struct xfs_trans *trans,
2132 struct xfs_inode *dp,
2133 xfs_dablk_t bno,
2134 xfs_daddr_t mappedbno,
2135 struct xfs_buf **bpp,
2136 int whichfork)
2137 {
2138 struct xfs_buf *bp;
2139 struct xfs_buf_map map;
2140 struct xfs_buf_map *mapp;
2141 int nmap;
2142 int error;
2143
2144 *bpp = NULL;
2145 mapp = &map;
2146 nmap = 1;
2147 error = xfs_dabuf_map(trans, dp, bno, mappedbno, whichfork,
2148 &mapp, &nmap);
2149 if (error) {
2150 /* mapping a hole is not an error, but we don't continue */
2151 if (error == -1)
2152 error = 0;
2153 goto out_free;
2154 }
2155
2156 error = xfs_trans_read_buf_map(dp->i_mount, trans,
2157 dp->i_mount->m_ddev_targp,
2158 mapp, nmap, 0, &bp);
2159 if (error)
2160 goto out_free;
2161
2162 if (whichfork == XFS_ATTR_FORK)
2163 xfs_buf_set_ref(bp, XFS_ATTR_BTREE_REF);
2164 else
2165 xfs_buf_set_ref(bp, XFS_DIR_BTREE_REF);
2166
2167 /*
2168 * This verification code will be moved to a CRC verification callback
2169 * function so just leave it here unchanged until then.
2170 */
2171 {
2172 xfs_dir2_data_hdr_t *hdr = bp->b_addr;
2173 xfs_dir2_free_t *free = bp->b_addr;
2174 xfs_da_blkinfo_t *info = bp->b_addr;
2175 uint magic, magic1;
2176 struct xfs_mount *mp = dp->i_mount;
2177
2178 magic = be16_to_cpu(info->magic);
2179 magic1 = be32_to_cpu(hdr->magic);
2180 if (unlikely(
2181 XFS_TEST_ERROR((magic != XFS_DA_NODE_MAGIC) &&
2182 (magic != XFS_ATTR_LEAF_MAGIC) &&
2183 (magic != XFS_DIR2_LEAF1_MAGIC) &&
2184 (magic != XFS_DIR2_LEAFN_MAGIC) &&
2185 (magic1 != XFS_DIR2_BLOCK_MAGIC) &&
2186 (magic1 != XFS_DIR2_DATA_MAGIC) &&
2187 (free->hdr.magic != cpu_to_be32(XFS_DIR2_FREE_MAGIC)),
2188 mp, XFS_ERRTAG_DA_READ_BUF,
2189 XFS_RANDOM_DA_READ_BUF))) {
2190 trace_xfs_da_btree_corrupt(bp, _RET_IP_);
2191 XFS_CORRUPTION_ERROR("xfs_da_do_buf(2)",
2192 XFS_ERRLEVEL_LOW, mp, info);
2193 error = XFS_ERROR(EFSCORRUPTED);
2194 xfs_trans_brelse(trans, bp);
2195 goto out_free;
2196 }
2197 }
2198 *bpp = bp;
2199 out_free:
2200 if (mapp != &map)
2201 kmem_free(mapp);
2202
2203 return error;
2204 }
2205
2206 /*
2207 * Readahead the dir/attr block.
2208 */
2209 xfs_daddr_t
2210 xfs_da_reada_buf(
2211 struct xfs_trans *trans,
2212 struct xfs_inode *dp,
2213 xfs_dablk_t bno,
2214 int whichfork)
2215 {
2216 xfs_daddr_t mappedbno = -1;
2217 struct xfs_buf_map map;
2218 struct xfs_buf_map *mapp;
2219 int nmap;
2220 int error;
2221
2222 mapp = &map;
2223 nmap = 1;
2224 error = xfs_dabuf_map(trans, dp, bno, -1, whichfork,
2225 &mapp, &nmap);
2226 if (error) {
2227 /* mapping a hole is not an error, but we don't continue */
2228 if (error == -1)
2229 error = 0;
2230 goto out_free;
2231 }
2232
2233 mappedbno = mapp[0].bm_bn;
2234 xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap);
2235
2236 out_free:
2237 if (mapp != &map)
2238 kmem_free(mapp);
2239
2240 if (error)
2241 return -1;
2242 return mappedbno;
2243 }
2244
2245 kmem_zone_t *xfs_da_state_zone; /* anchor for state struct zone */
2246
2247 /*
2248 * Allocate a dir-state structure.
2249 * We don't put them on the stack since they're large.
2250 */
2251 xfs_da_state_t *
2252 xfs_da_state_alloc(void)
2253 {
2254 return kmem_zone_zalloc(xfs_da_state_zone, KM_NOFS);
2255 }
2256
2257 /*
2258 * Kill the altpath contents of a da-state structure.
2259 */
2260 STATIC void
2261 xfs_da_state_kill_altpath(xfs_da_state_t *state)
2262 {
2263 int i;
2264
2265 for (i = 0; i < state->altpath.active; i++)
2266 state->altpath.blk[i].bp = NULL;
2267 state->altpath.active = 0;
2268 }
2269
2270 /*
2271 * Free a da-state structure.
2272 */
2273 void
2274 xfs_da_state_free(xfs_da_state_t *state)
2275 {
2276 xfs_da_state_kill_altpath(state);
2277 #ifdef DEBUG
2278 memset((char *)state, 0, sizeof(*state));
2279 #endif /* DEBUG */
2280 kmem_zone_free(xfs_da_state_zone, state);
2281 }
Linux 2.6 libata-dev (mirror)