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fed up with those stupid warnings
[mmotm.git] / fs / jfs / jfs_xtree.c
blobd654a6458648d1a3427be4924f5463f5d77d5f40
1 /*
2 * Copyright (C) International Business Machines Corp., 2000-2005
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the 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 to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18 /*
19 * jfs_xtree.c: extent allocation descriptor B+-tree manager
20 */
21
22 #include <linux/fs.h>
23 #include <linux/module.h>
24 #include <linux/quotaops.h>
25 #include <linux/seq_file.h>
26 #include "jfs_incore.h"
27 #include "jfs_filsys.h"
28 #include "jfs_metapage.h"
29 #include "jfs_dmap.h"
30 #include "jfs_dinode.h"
31 #include "jfs_superblock.h"
32 #include "jfs_debug.h"
33
34 /*
35 * xtree local flag
36 */
37 #define XT_INSERT 0x00000001
38
39 /*
40 * xtree key/entry comparison: extent offset
41 *
42 * return:
43 * -1: k < start of extent
44 * 0: start_of_extent <= k <= end_of_extent
45 * 1: k > end_of_extent
46 */
47 #define XT_CMP(CMP, K, X, OFFSET64)\
48 {\
49 OFFSET64 = offsetXAD(X);\
50 (CMP) = ((K) >= OFFSET64 + lengthXAD(X)) ? 1 :\
51 ((K) < OFFSET64) ? -1 : 0;\
52 }
53
54 /* write a xad entry */
55 #define XT_PUTENTRY(XAD, FLAG, OFF, LEN, ADDR)\
56 {\
57 (XAD)->flag = (FLAG);\
58 XADoffset((XAD), (OFF));\
59 XADlength((XAD), (LEN));\
60 XADaddress((XAD), (ADDR));\
61 }
62
63 #define XT_PAGE(IP, MP) BT_PAGE(IP, MP, xtpage_t, i_xtroot)
64
65 /* get page buffer for specified block address */
66 /* ToDo: Replace this ugly macro with a function */
67 #define XT_GETPAGE(IP, BN, MP, SIZE, P, RC)\
68 {\
69 BT_GETPAGE(IP, BN, MP, xtpage_t, SIZE, P, RC, i_xtroot)\
70 if (!(RC))\
71 {\
72 if ((le16_to_cpu((P)->header.nextindex) < XTENTRYSTART) ||\
73 (le16_to_cpu((P)->header.nextindex) > le16_to_cpu((P)->header.maxentry)) ||\
74 (le16_to_cpu((P)->header.maxentry) > (((BN)==0)?XTROOTMAXSLOT:PSIZE>>L2XTSLOTSIZE)))\
75 {\
76 jfs_error((IP)->i_sb, "XT_GETPAGE: xtree page corrupt");\
77 BT_PUTPAGE(MP);\
78 MP = NULL;\
79 RC = -EIO;\
80 }\
81 }\
82 }
83
84 /* for consistency */
85 #define XT_PUTPAGE(MP) BT_PUTPAGE(MP)
86
87 #define XT_GETSEARCH(IP, LEAF, BN, MP, P, INDEX) \
88 BT_GETSEARCH(IP, LEAF, BN, MP, xtpage_t, P, INDEX, i_xtroot)
89 /* xtree entry parameter descriptor */
90 struct xtsplit {
91 struct metapage *mp;
92 s16 index;
93 u8 flag;
94 s64 off;
95 s64 addr;
96 int len;
97 struct pxdlist *pxdlist;
98 };
99
100
101 /*
102 * statistics
103 */
104 #ifdef CONFIG_JFS_STATISTICS
105 static struct {
106 uint search;
107 uint fastSearch;
108 uint split;
109 } xtStat;
110 #endif
111
112
113 /*
114 * forward references
115 */
116 static int xtSearch(struct inode *ip, s64 xoff, s64 *next, int *cmpp,
117 struct btstack * btstack, int flag);
118
119 static int xtSplitUp(tid_t tid,
120 struct inode *ip,
121 struct xtsplit * split, struct btstack * btstack);
122
123 static int xtSplitPage(tid_t tid, struct inode *ip, struct xtsplit * split,
124 struct metapage ** rmpp, s64 * rbnp);
125
126 static int xtSplitRoot(tid_t tid, struct inode *ip,
127 struct xtsplit * split, struct metapage ** rmpp);
128
129 #ifdef _STILL_TO_PORT
130 static int xtDeleteUp(tid_t tid, struct inode *ip, struct metapage * fmp,
131 xtpage_t * fp, struct btstack * btstack);
132
133 static int xtSearchNode(struct inode *ip,
134 xad_t * xad,
135 int *cmpp, struct btstack * btstack, int flag);
136
137 static int xtRelink(tid_t tid, struct inode *ip, xtpage_t * fp);
138 #endif /* _STILL_TO_PORT */
139
140 /*
141 * xtLookup()
142 *
143 * function: map a single page into a physical extent;
144 */
145 int xtLookup(struct inode *ip, s64 lstart,
146 s64 llen, int *pflag, s64 * paddr, s32 * plen, int no_check)
147 {
148 int rc = 0;
149 struct btstack btstack;
150 int cmp;
151 s64 bn;
152 struct metapage *mp;
153 xtpage_t *p;
154 int index;
155 xad_t *xad;
156 s64 next, size, xoff, xend;
157 int xlen;
158 s64 xaddr;
159
160 *paddr = 0;
161 *plen = llen;
162
163 if (!no_check) {
164 /* is lookup offset beyond eof ? */
165 size = ((u64) ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
166 JFS_SBI(ip->i_sb)->l2bsize;
167 if (lstart >= size)
168 return 0;
169 }
170
171 /*
172 * search for the xad entry covering the logical extent
173 */
174 //search:
175 if ((rc = xtSearch(ip, lstart, &next, &cmp, &btstack, 0))) {
176 jfs_err("xtLookup: xtSearch returned %d", rc);
177 return rc;
178 }
179
180 /*
181 * compute the physical extent covering logical extent
182 *
183 * N.B. search may have failed (e.g., hole in sparse file),
184 * and returned the index of the next entry.
185 */
186 /* retrieve search result */
187 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
188
189 /* is xad found covering start of logical extent ?
190 * lstart is a page start address,
191 * i.e., lstart cannot start in a hole;
192 */
193 if (cmp) {
194 if (next)
195 *plen = min(next - lstart, llen);
196 goto out;
197 }
198
199 /*
200 * lxd covered by xad
201 */
202 xad = &p->xad[index];
203 xoff = offsetXAD(xad);
204 xlen = lengthXAD(xad);
205 xend = xoff + xlen;
206 xaddr = addressXAD(xad);
207
208 /* initialize new pxd */
209 *pflag = xad->flag;
210 *paddr = xaddr + (lstart - xoff);
211 /* a page must be fully covered by an xad */
212 *plen = min(xend - lstart, llen);
213
214 out:
215 XT_PUTPAGE(mp);
216
217 return rc;
218 }
219
220 /*
221 * xtSearch()
222 *
223 * function: search for the xad entry covering specified offset.
224 *
225 * parameters:
226 * ip - file object;
227 * xoff - extent offset;
228 * nextp - address of next extent (if any) for search miss
229 * cmpp - comparison result:
230 * btstack - traverse stack;
231 * flag - search process flag (XT_INSERT);
232 *
233 * returns:
234 * btstack contains (bn, index) of search path traversed to the entry.
235 * *cmpp is set to result of comparison with the entry returned.
236 * the page containing the entry is pinned at exit.
237 */
238 static int xtSearch(struct inode *ip, s64 xoff, s64 *nextp,
239 int *cmpp, struct btstack * btstack, int flag)
240 {
241 struct jfs_inode_info *jfs_ip = JFS_IP(ip);
242 int rc = 0;
243 int cmp = 1; /* init for empty page */
244 s64 bn; /* block number */
245 struct metapage *mp; /* page buffer */
246 xtpage_t *p; /* page */
247 xad_t *xad;
248 int base, index, lim, btindex;
249 struct btframe *btsp;
250 int nsplit = 0; /* number of pages to split */
251 s64 t64;
252 s64 next = 0;
253
254 INCREMENT(xtStat.search);
255
256 BT_CLR(btstack);
257
258 btstack->nsplit = 0;
259
260 /*
261 * search down tree from root:
262 *
263 * between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
264 * internal page, child page Pi contains entry with k, Ki <= K < Kj.
265 *
266 * if entry with search key K is not found
267 * internal page search find the entry with largest key Ki
268 * less than K which point to the child page to search;
269 * leaf page search find the entry with smallest key Kj
270 * greater than K so that the returned index is the position of
271 * the entry to be shifted right for insertion of new entry.
272 * for empty tree, search key is greater than any key of the tree.
273 *
274 * by convention, root bn = 0.
275 */
276 for (bn = 0;;) {
277 /* get/pin the page to search */
278 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
279 if (rc)
280 return rc;
281
282 /* try sequential access heuristics with the previous
283 * access entry in target leaf page:
284 * once search narrowed down into the target leaf,
285 * key must either match an entry in the leaf or
286 * key entry does not exist in the tree;
287 */
288 //fastSearch:
289 if ((jfs_ip->btorder & BT_SEQUENTIAL) &&
290 (p->header.flag & BT_LEAF) &&
291 (index = jfs_ip->btindex) <
292 le16_to_cpu(p->header.nextindex)) {
293 xad = &p->xad[index];
294 t64 = offsetXAD(xad);
295 if (xoff < t64 + lengthXAD(xad)) {
296 if (xoff >= t64) {
297 *cmpp = 0;
298 goto out;
299 }
300
301 /* stop sequential access heuristics */
302 goto binarySearch;
303 } else { /* (t64 + lengthXAD(xad)) <= xoff */
304
305 /* try next sequential entry */
306 index++;
307 if (index <
308 le16_to_cpu(p->header.nextindex)) {
309 xad++;
310 t64 = offsetXAD(xad);
311 if (xoff < t64 + lengthXAD(xad)) {
312 if (xoff >= t64) {
313 *cmpp = 0;
314 goto out;
315 }
316
317 /* miss: key falls between
318 * previous and this entry
319 */
320 *cmpp = 1;
321 next = t64;
322 goto out;
323 }
324
325 /* (xoff >= t64 + lengthXAD(xad));
326 * matching entry may be further out:
327 * stop heuristic search
328 */
329 /* stop sequential access heuristics */
330 goto binarySearch;
331 }
332
333 /* (index == p->header.nextindex);
334 * miss: key entry does not exist in
335 * the target leaf/tree
336 */
337 *cmpp = 1;
338 goto out;
339 }
340
341 /*
342 * if hit, return index of the entry found, and
343 * if miss, where new entry with search key is
344 * to be inserted;
345 */
346 out:
347 /* compute number of pages to split */
348 if (flag & XT_INSERT) {
349 if (p->header.nextindex == /* little-endian */
350 p->header.maxentry)
351 nsplit++;
352 else
353 nsplit = 0;
354 btstack->nsplit = nsplit;
355 }
356
357 /* save search result */
358 btsp = btstack->top;
359 btsp->bn = bn;
360 btsp->index = index;
361 btsp->mp = mp;
362
363 /* update sequential access heuristics */
364 jfs_ip->btindex = index;
365
366 if (nextp)
367 *nextp = next;
368
369 INCREMENT(xtStat.fastSearch);
370 return 0;
371 }
372
373 /* well, ... full search now */
374 binarySearch:
375 lim = le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
376
377 /*
378 * binary search with search key K on the current page
379 */
380 for (base = XTENTRYSTART; lim; lim >>= 1) {
381 index = base + (lim >> 1);
382
383 XT_CMP(cmp, xoff, &p->xad[index], t64);
384 if (cmp == 0) {
385 /*
386 * search hit
387 */
388 /* search hit - leaf page:
389 * return the entry found
390 */
391 if (p->header.flag & BT_LEAF) {
392 *cmpp = cmp;
393
394 /* compute number of pages to split */
395 if (flag & XT_INSERT) {
396 if (p->header.nextindex ==
397 p->header.maxentry)
398 nsplit++;
399 else
400 nsplit = 0;
401 btstack->nsplit = nsplit;
402 }
403
404 /* save search result */
405 btsp = btstack->top;
406 btsp->bn = bn;
407 btsp->index = index;
408 btsp->mp = mp;
409
410 /* init sequential access heuristics */
411 btindex = jfs_ip->btindex;
412 if (index == btindex ||
413 index == btindex + 1)
414 jfs_ip->btorder = BT_SEQUENTIAL;
415 else
416 jfs_ip->btorder = BT_RANDOM;
417 jfs_ip->btindex = index;
418
419 return 0;
420 }
421 /* search hit - internal page:
422 * descend/search its child page
423 */
424 if (index < le16_to_cpu(p->header.nextindex)-1)
425 next = offsetXAD(&p->xad[index + 1]);
426 goto next;
427 }
428
429 if (cmp > 0) {
430 base = index + 1;
431 --lim;
432 }
433 }
434
435 /*
436 * search miss
437 *
438 * base is the smallest index with key (Kj) greater than
439 * search key (K) and may be zero or maxentry index.
440 */
441 if (base < le16_to_cpu(p->header.nextindex))
442 next = offsetXAD(&p->xad[base]);
443 /*
444 * search miss - leaf page:
445 *
446 * return location of entry (base) where new entry with
447 * search key K is to be inserted.
448 */
449 if (p->header.flag & BT_LEAF) {
450 *cmpp = cmp;
451
452 /* compute number of pages to split */
453 if (flag & XT_INSERT) {
454 if (p->header.nextindex ==
455 p->header.maxentry)
456 nsplit++;
457 else
458 nsplit = 0;
459 btstack->nsplit = nsplit;
460 }
461
462 /* save search result */
463 btsp = btstack->top;
464 btsp->bn = bn;
465 btsp->index = base;
466 btsp->mp = mp;
467
468 /* init sequential access heuristics */
469 btindex = jfs_ip->btindex;
470 if (base == btindex || base == btindex + 1)
471 jfs_ip->btorder = BT_SEQUENTIAL;
472 else
473 jfs_ip->btorder = BT_RANDOM;
474 jfs_ip->btindex = base;
475
476 if (nextp)
477 *nextp = next;
478
479 return 0;
480 }
481
482 /*
483 * search miss - non-leaf page:
484 *
485 * if base is non-zero, decrement base by one to get the parent
486 * entry of the child page to search.
487 */
488 index = base ? base - 1 : base;
489
490 /*
491 * go down to child page
492 */
493 next:
494 /* update number of pages to split */
495 if (p->header.nextindex == p->header.maxentry)
496 nsplit++;
497 else
498 nsplit = 0;
499
500 /* push (bn, index) of the parent page/entry */
501 if (BT_STACK_FULL(btstack)) {
502 jfs_error(ip->i_sb, "stack overrun in xtSearch!");
503 XT_PUTPAGE(mp);
504 return -EIO;
505 }
506 BT_PUSH(btstack, bn, index);
507
508 /* get the child page block number */
509 bn = addressXAD(&p->xad[index]);
510
511 /* unpin the parent page */
512 XT_PUTPAGE(mp);
513 }
514 }
515
516 /*
517 * xtInsert()
518 *
519 * function:
520 *
521 * parameter:
522 * tid - transaction id;
523 * ip - file object;
524 * xflag - extent flag (XAD_NOTRECORDED):
525 * xoff - extent offset;
526 * xlen - extent length;
527 * xaddrp - extent address pointer (in/out):
528 * if (*xaddrp)
529 * caller allocated data extent at *xaddrp;
530 * else
531 * allocate data extent and return its xaddr;
532 * flag -
533 *
534 * return:
535 */
536 int xtInsert(tid_t tid, /* transaction id */
537 struct inode *ip, int xflag, s64 xoff, s32 xlen, s64 * xaddrp,
538 int flag)
539 {
540 int rc = 0;
541 s64 xaddr, hint;
542 struct metapage *mp; /* meta-page buffer */
543 xtpage_t *p; /* base B+-tree index page */
544 s64 bn;
545 int index, nextindex;
546 struct btstack btstack; /* traverse stack */
547 struct xtsplit split; /* split information */
548 xad_t *xad;
549 int cmp;
550 s64 next;
551 struct tlock *tlck;
552 struct xtlock *xtlck;
553
554 jfs_info("xtInsert: nxoff:0x%lx nxlen:0x%x", (ulong) xoff, xlen);
555
556 /*
557 * search for the entry location at which to insert:
558 *
559 * xtFastSearch() and xtSearch() both returns (leaf page
560 * pinned, index at which to insert).
561 * n.b. xtSearch() may return index of maxentry of
562 * the full page.
563 */
564 if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
565 return rc;
566
567 /* retrieve search result */
568 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
569
570 /* This test must follow XT_GETSEARCH since mp must be valid if
571 * we branch to out: */
572 if ((cmp == 0) || (next && (xlen > next - xoff))) {
573 rc = -EEXIST;
574 goto out;
575 }
576
577 /*
578 * allocate data extent requested
579 *
580 * allocation hint: last xad
581 */
582 if ((xaddr = *xaddrp) == 0) {
583 if (index > XTENTRYSTART) {
584 xad = &p->xad[index - 1];
585 hint = addressXAD(xad) + lengthXAD(xad) - 1;
586 } else
587 hint = 0;
588 if ((rc = vfs_dq_alloc_block(ip, xlen)))
589 goto out;
590 if ((rc = dbAlloc(ip, hint, (s64) xlen, &xaddr))) {
591 vfs_dq_free_block(ip, xlen);
592 goto out;
593 }
594 }
595
596 /*
597 * insert entry for new extent
598 */
599 xflag |= XAD_NEW;
600
601 /*
602 * if the leaf page is full, split the page and
603 * propagate up the router entry for the new page from split
604 *
605 * The xtSplitUp() will insert the entry and unpin the leaf page.
606 */
607 nextindex = le16_to_cpu(p->header.nextindex);
608 if (nextindex == le16_to_cpu(p->header.maxentry)) {
609 split.mp = mp;
610 split.index = index;
611 split.flag = xflag;
612 split.off = xoff;
613 split.len = xlen;
614 split.addr = xaddr;
615 split.pxdlist = NULL;
616 if ((rc = xtSplitUp(tid, ip, &split, &btstack))) {
617 /* undo data extent allocation */
618 if (*xaddrp == 0) {
619 dbFree(ip, xaddr, (s64) xlen);
620 vfs_dq_free_block(ip, xlen);
621 }
622 return rc;
623 }
624
625 *xaddrp = xaddr;
626 return 0;
627 }
628
629 /*
630 * insert the new entry into the leaf page
631 */
632 /*
633 * acquire a transaction lock on the leaf page;
634 *
635 * action: xad insertion/extension;
636 */
637 BT_MARK_DIRTY(mp, ip);
638
639 /* if insert into middle, shift right remaining entries. */
640 if (index < nextindex)
641 memmove(&p->xad[index + 1], &p->xad[index],
642 (nextindex - index) * sizeof(xad_t));
643
644 /* insert the new entry: mark the entry NEW */
645 xad = &p->xad[index];
646 XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
647
648 /* advance next available entry index */
649 le16_add_cpu(&p->header.nextindex, 1);
650
651 /* Don't log it if there are no links to the file */
652 if (!test_cflag(COMMIT_Nolink, ip)) {
653 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
654 xtlck = (struct xtlock *) & tlck->lock;
655 xtlck->lwm.offset =
656 (xtlck->lwm.offset) ? min(index,
657 (int)xtlck->lwm.offset) : index;
658 xtlck->lwm.length =
659 le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
660 }
661
662 *xaddrp = xaddr;
663
664 out:
665 /* unpin the leaf page */
666 XT_PUTPAGE(mp);
667
668 return rc;
669 }
670
671
672 /*
673 * xtSplitUp()
674 *
675 * function:
676 * split full pages as propagating insertion up the tree
677 *
678 * parameter:
679 * tid - transaction id;
680 * ip - file object;
681 * split - entry parameter descriptor;
682 * btstack - traverse stack from xtSearch()
683 *
684 * return:
685 */
686 static int
687 xtSplitUp(tid_t tid,
688 struct inode *ip, struct xtsplit * split, struct btstack * btstack)
689 {
690 int rc = 0;
691 struct metapage *smp;
692 xtpage_t *sp; /* split page */
693 struct metapage *rmp;
694 s64 rbn; /* new right page block number */
695 struct metapage *rcmp;
696 xtpage_t *rcp; /* right child page */
697 s64 rcbn; /* right child page block number */
698 int skip; /* index of entry of insertion */
699 int nextindex; /* next available entry index of p */
700 struct btframe *parent; /* parent page entry on traverse stack */
701 xad_t *xad;
702 s64 xaddr;
703 int xlen;
704 int nsplit; /* number of pages split */
705 struct pxdlist pxdlist;
706 pxd_t *pxd;
707 struct tlock *tlck;
708 struct xtlock *xtlck;
709
710 smp = split->mp;
711 sp = XT_PAGE(ip, smp);
712
713 /* is inode xtree root extension/inline EA area free ? */
714 if ((sp->header.flag & BT_ROOT) && (!S_ISDIR(ip->i_mode)) &&
715 (le16_to_cpu(sp->header.maxentry) < XTROOTMAXSLOT) &&
716 (JFS_IP(ip)->mode2 & INLINEEA)) {
717 sp->header.maxentry = cpu_to_le16(XTROOTMAXSLOT);
718 JFS_IP(ip)->mode2 &= ~INLINEEA;
719
720 BT_MARK_DIRTY(smp, ip);
721 /*
722 * acquire a transaction lock on the leaf page;
723 *
724 * action: xad insertion/extension;
725 */
726
727 /* if insert into middle, shift right remaining entries. */
728 skip = split->index;
729 nextindex = le16_to_cpu(sp->header.nextindex);
730 if (skip < nextindex)
731 memmove(&sp->xad[skip + 1], &sp->xad[skip],
732 (nextindex - skip) * sizeof(xad_t));
733
734 /* insert the new entry: mark the entry NEW */
735 xad = &sp->xad[skip];
736 XT_PUTENTRY(xad, split->flag, split->off, split->len,
737 split->addr);
738
739 /* advance next available entry index */
740 le16_add_cpu(&sp->header.nextindex, 1);
741
742 /* Don't log it if there are no links to the file */
743 if (!test_cflag(COMMIT_Nolink, ip)) {
744 tlck = txLock(tid, ip, smp, tlckXTREE | tlckGROW);
745 xtlck = (struct xtlock *) & tlck->lock;
746 xtlck->lwm.offset = (xtlck->lwm.offset) ?
747 min(skip, (int)xtlck->lwm.offset) : skip;
748 xtlck->lwm.length =
749 le16_to_cpu(sp->header.nextindex) -
750 xtlck->lwm.offset;
751 }
752
753 return 0;
754 }
755
756 /*
757 * allocate new index blocks to cover index page split(s)
758 *
759 * allocation hint: ?
760 */
761 if (split->pxdlist == NULL) {
762 nsplit = btstack->nsplit;
763 split->pxdlist = &pxdlist;
764 pxdlist.maxnpxd = pxdlist.npxd = 0;
765 pxd = &pxdlist.pxd[0];
766 xlen = JFS_SBI(ip->i_sb)->nbperpage;
767 for (; nsplit > 0; nsplit--, pxd++) {
768 if ((rc = dbAlloc(ip, (s64) 0, (s64) xlen, &xaddr))
769 == 0) {
770 PXDaddress(pxd, xaddr);
771 PXDlength(pxd, xlen);
772
773 pxdlist.maxnpxd++;
774
775 continue;
776 }
777
778 /* undo allocation */
779
780 XT_PUTPAGE(smp);
781 return rc;
782 }
783 }
784
785 /*
786 * Split leaf page <sp> into <sp> and a new right page <rp>.
787 *
788 * The split routines insert the new entry into the leaf page,
789 * and acquire txLock as appropriate.
790 * return <rp> pinned and its block number <rpbn>.
791 */
792 rc = (sp->header.flag & BT_ROOT) ?
793 xtSplitRoot(tid, ip, split, &rmp) :
794 xtSplitPage(tid, ip, split, &rmp, &rbn);
795
796 XT_PUTPAGE(smp);
797
798 if (rc)
799 return -EIO;
800 /*
801 * propagate up the router entry for the leaf page just split
802 *
803 * insert a router entry for the new page into the parent page,
804 * propagate the insert/split up the tree by walking back the stack
805 * of (bn of parent page, index of child page entry in parent page)
806 * that were traversed during the search for the page that split.
807 *
808 * the propagation of insert/split up the tree stops if the root
809 * splits or the page inserted into doesn't have to split to hold
810 * the new entry.
811 *
812 * the parent entry for the split page remains the same, and
813 * a new entry is inserted at its right with the first key and
814 * block number of the new right page.
815 *
816 * There are a maximum of 3 pages pinned at any time:
817 * right child, left parent and right parent (when the parent splits)
818 * to keep the child page pinned while working on the parent.
819 * make sure that all pins are released at exit.
820 */
821 while ((parent = BT_POP(btstack)) != NULL) {
822 /* parent page specified by stack frame <parent> */
823
824 /* keep current child pages <rcp> pinned */
825 rcmp = rmp;
826 rcbn = rbn;
827 rcp = XT_PAGE(ip, rcmp);
828
829 /*
830 * insert router entry in parent for new right child page <rp>
831 */
832 /* get/pin the parent page <sp> */
833 XT_GETPAGE(ip, parent->bn, smp, PSIZE, sp, rc);
834 if (rc) {
835 XT_PUTPAGE(rcmp);
836 return rc;
837 }
838
839 /*
840 * The new key entry goes ONE AFTER the index of parent entry,
841 * because the split was to the right.
842 */
843 skip = parent->index + 1;
844
845 /*
846 * split or shift right remaining entries of the parent page
847 */
848 nextindex = le16_to_cpu(sp->header.nextindex);
849 /*
850 * parent page is full - split the parent page
851 */
852 if (nextindex == le16_to_cpu(sp->header.maxentry)) {
853 /* init for parent page split */
854 split->mp = smp;
855 split->index = skip; /* index at insert */
856 split->flag = XAD_NEW;
857 split->off = offsetXAD(&rcp->xad[XTENTRYSTART]);
858 split->len = JFS_SBI(ip->i_sb)->nbperpage;
859 split->addr = rcbn;
860
861 /* unpin previous right child page */
862 XT_PUTPAGE(rcmp);
863
864 /* The split routines insert the new entry,
865 * and acquire txLock as appropriate.
866 * return <rp> pinned and its block number <rpbn>.
867 */
868 rc = (sp->header.flag & BT_ROOT) ?
869 xtSplitRoot(tid, ip, split, &rmp) :
870 xtSplitPage(tid, ip, split, &rmp, &rbn);
871 if (rc) {
872 XT_PUTPAGE(smp);
873 return rc;
874 }
875
876 XT_PUTPAGE(smp);
877 /* keep new child page <rp> pinned */
878 }
879 /*
880 * parent page is not full - insert in parent page
881 */
882 else {
883 /*
884 * insert router entry in parent for the right child
885 * page from the first entry of the right child page:
886 */
887 /*
888 * acquire a transaction lock on the parent page;
889 *
890 * action: router xad insertion;
891 */
892 BT_MARK_DIRTY(smp, ip);
893
894 /*
895 * if insert into middle, shift right remaining entries
896 */
897 if (skip < nextindex)
898 memmove(&sp->xad[skip + 1], &sp->xad[skip],
899 (nextindex -
900 skip) << L2XTSLOTSIZE);
901
902 /* insert the router entry */
903 xad = &sp->xad[skip];
904 XT_PUTENTRY(xad, XAD_NEW,
905 offsetXAD(&rcp->xad[XTENTRYSTART]),
906 JFS_SBI(ip->i_sb)->nbperpage, rcbn);
907
908 /* advance next available entry index. */
909 le16_add_cpu(&sp->header.nextindex, 1);
910
911 /* Don't log it if there are no links to the file */
912 if (!test_cflag(COMMIT_Nolink, ip)) {
913 tlck = txLock(tid, ip, smp,
914 tlckXTREE | tlckGROW);
915 xtlck = (struct xtlock *) & tlck->lock;
916 xtlck->lwm.offset = (xtlck->lwm.offset) ?
917 min(skip, (int)xtlck->lwm.offset) : skip;
918 xtlck->lwm.length =
919 le16_to_cpu(sp->header.nextindex) -
920 xtlck->lwm.offset;
921 }
922
923 /* unpin parent page */
924 XT_PUTPAGE(smp);
925
926 /* exit propagate up */
927 break;
928 }
929 }
930
931 /* unpin current right page */
932 XT_PUTPAGE(rmp);
933
934 return 0;
935 }
936
937
938 /*
939 * xtSplitPage()
940 *
941 * function:
942 * split a full non-root page into
943 * original/split/left page and new right page
944 * i.e., the original/split page remains as left page.
945 *
946 * parameter:
947 * int tid,
948 * struct inode *ip,
949 * struct xtsplit *split,
950 * struct metapage **rmpp,
951 * u64 *rbnp,
952 *
953 * return:
954 * Pointer to page in which to insert or NULL on error.
955 */
956 static int
957 xtSplitPage(tid_t tid, struct inode *ip,
958 struct xtsplit * split, struct metapage ** rmpp, s64 * rbnp)
959 {
960 int rc = 0;
961 struct metapage *smp;
962 xtpage_t *sp;
963 struct metapage *rmp;
964 xtpage_t *rp; /* new right page allocated */
965 s64 rbn; /* new right page block number */
966 struct metapage *mp;
967 xtpage_t *p;
968 s64 nextbn;
969 int skip, maxentry, middle, righthalf, n;
970 xad_t *xad;
971 struct pxdlist *pxdlist;
972 pxd_t *pxd;
973 struct tlock *tlck;
974 struct xtlock *sxtlck = NULL, *rxtlck = NULL;
975 int quota_allocation = 0;
976
977 smp = split->mp;
978 sp = XT_PAGE(ip, smp);
979
980 INCREMENT(xtStat.split);
981
982 pxdlist = split->pxdlist;
983 pxd = &pxdlist->pxd[pxdlist->npxd];
984 pxdlist->npxd++;
985 rbn = addressPXD(pxd);
986
987 /* Allocate blocks to quota. */
988 if (vfs_dq_alloc_block(ip, lengthPXD(pxd))) {
989 rc = -EDQUOT;
990 goto clean_up;
991 }
992
993 quota_allocation += lengthPXD(pxd);
994
995 /*
996 * allocate the new right page for the split
997 */
998 rmp = get_metapage(ip, rbn, PSIZE, 1);
999 if (rmp == NULL) {
1000 rc = -EIO;
1001 goto clean_up;
1002 }
1003
1004 jfs_info("xtSplitPage: ip:0x%p smp:0x%p rmp:0x%p", ip, smp, rmp);
1005
1006 BT_MARK_DIRTY(rmp, ip);
1007 /*
1008 * action: new page;
1009 */
1010
1011 rp = (xtpage_t *) rmp->data;
1012 rp->header.self = *pxd;
1013 rp->header.flag = sp->header.flag & BT_TYPE;
1014 rp->header.maxentry = sp->header.maxentry; /* little-endian */
1015 rp->header.nextindex = cpu_to_le16(XTENTRYSTART);
1016
1017 BT_MARK_DIRTY(smp, ip);
1018 /* Don't log it if there are no links to the file */
1019 if (!test_cflag(COMMIT_Nolink, ip)) {
1020 /*
1021 * acquire a transaction lock on the new right page;
1022 */
1023 tlck = txLock(tid, ip, rmp, tlckXTREE | tlckNEW);
1024 rxtlck = (struct xtlock *) & tlck->lock;
1025 rxtlck->lwm.offset = XTENTRYSTART;
1026 /*
1027 * acquire a transaction lock on the split page
1028 */
1029 tlck = txLock(tid, ip, smp, tlckXTREE | tlckGROW);
1030 sxtlck = (struct xtlock *) & tlck->lock;
1031 }
1032
1033 /*
1034 * initialize/update sibling pointers of <sp> and <rp>
1035 */
1036 nextbn = le64_to_cpu(sp->header.next);
1037 rp->header.next = cpu_to_le64(nextbn);
1038 rp->header.prev = cpu_to_le64(addressPXD(&sp->header.self));
1039 sp->header.next = cpu_to_le64(rbn);
1040
1041 skip = split->index;
1042
1043 /*
1044 * sequential append at tail (after last entry of last page)
1045 *
1046 * if splitting the last page on a level because of appending
1047 * a entry to it (skip is maxentry), it's likely that the access is
1048 * sequential. adding an empty page on the side of the level is less
1049 * work and can push the fill factor much higher than normal.
1050 * if we're wrong it's no big deal - we will do the split the right
1051 * way next time.
1052 * (it may look like it's equally easy to do a similar hack for
1053 * reverse sorted data, that is, split the tree left, but it's not.
1054 * Be my guest.)
1055 */
1056 if (nextbn == 0 && skip == le16_to_cpu(sp->header.maxentry)) {
1057 /*
1058 * acquire a transaction lock on the new/right page;
1059 *
1060 * action: xad insertion;
1061 */
1062 /* insert entry at the first entry of the new right page */
1063 xad = &rp->xad[XTENTRYSTART];
1064 XT_PUTENTRY(xad, split->flag, split->off, split->len,
1065 split->addr);
1066
1067 rp->header.nextindex = cpu_to_le16(XTENTRYSTART + 1);
1068
1069 if (!test_cflag(COMMIT_Nolink, ip)) {
1070 /* rxtlck->lwm.offset = XTENTRYSTART; */
1071 rxtlck->lwm.length = 1;
1072 }
1073
1074 *rmpp = rmp;
1075 *rbnp = rbn;
1076
1077 jfs_info("xtSplitPage: sp:0x%p rp:0x%p", sp, rp);
1078 return 0;
1079 }
1080
1081 /*
1082 * non-sequential insert (at possibly middle page)
1083 */
1084
1085 /*
1086 * update previous pointer of old next/right page of <sp>
1087 */
1088 if (nextbn != 0) {
1089 XT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
1090 if (rc) {
1091 XT_PUTPAGE(rmp);
1092 goto clean_up;
1093 }
1094
1095 BT_MARK_DIRTY(mp, ip);
1096 /*
1097 * acquire a transaction lock on the next page;
1098 *
1099 * action:sibling pointer update;
1100 */
1101 if (!test_cflag(COMMIT_Nolink, ip))
1102 tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
1103
1104 p->header.prev = cpu_to_le64(rbn);
1105
1106 /* sibling page may have been updated previously, or
1107 * it may be updated later;
1108 */
1109
1110 XT_PUTPAGE(mp);
1111 }
1112
1113 /*
1114 * split the data between the split and new/right pages
1115 */
1116 maxentry = le16_to_cpu(sp->header.maxentry);
1117 middle = maxentry >> 1;
1118 righthalf = maxentry - middle;
1119
1120 /*
1121 * skip index in old split/left page - insert into left page:
1122 */
1123 if (skip <= middle) {
1124 /* move right half of split page to the new right page */
1125 memmove(&rp->xad[XTENTRYSTART], &sp->xad[middle],
1126 righthalf << L2XTSLOTSIZE);
1127
1128 /* shift right tail of left half to make room for new entry */
1129 if (skip < middle)
1130 memmove(&sp->xad[skip + 1], &sp->xad[skip],
1131 (middle - skip) << L2XTSLOTSIZE);
1132
1133 /* insert new entry */
1134 xad = &sp->xad[skip];
1135 XT_PUTENTRY(xad, split->flag, split->off, split->len,
1136 split->addr);
1137
1138 /* update page header */
1139 sp->header.nextindex = cpu_to_le16(middle + 1);
1140 if (!test_cflag(COMMIT_Nolink, ip)) {
1141 sxtlck->lwm.offset = (sxtlck->lwm.offset) ?
1142 min(skip, (int)sxtlck->lwm.offset) : skip;
1143 }
1144
1145 rp->header.nextindex =
1146 cpu_to_le16(XTENTRYSTART + righthalf);
1147 }
1148 /*
1149 * skip index in new right page - insert into right page:
1150 */
1151 else {
1152 /* move left head of right half to right page */
1153 n = skip - middle;
1154 memmove(&rp->xad[XTENTRYSTART], &sp->xad[middle],
1155 n << L2XTSLOTSIZE);
1156
1157 /* insert new entry */
1158 n += XTENTRYSTART;
1159 xad = &rp->xad[n];
1160 XT_PUTENTRY(xad, split->flag, split->off, split->len,
1161 split->addr);
1162
1163 /* move right tail of right half to right page */
1164 if (skip < maxentry)
1165 memmove(&rp->xad[n + 1], &sp->xad[skip],
1166 (maxentry - skip) << L2XTSLOTSIZE);
1167
1168 /* update page header */
1169 sp->header.nextindex = cpu_to_le16(middle);
1170 if (!test_cflag(COMMIT_Nolink, ip)) {
1171 sxtlck->lwm.offset = (sxtlck->lwm.offset) ?
1172 min(middle, (int)sxtlck->lwm.offset) : middle;
1173 }
1174
1175 rp->header.nextindex = cpu_to_le16(XTENTRYSTART +
1176 righthalf + 1);
1177 }
1178
1179 if (!test_cflag(COMMIT_Nolink, ip)) {
1180 sxtlck->lwm.length = le16_to_cpu(sp->header.nextindex) -
1181 sxtlck->lwm.offset;
1182
1183 /* rxtlck->lwm.offset = XTENTRYSTART; */
1184 rxtlck->lwm.length = le16_to_cpu(rp->header.nextindex) -
1185 XTENTRYSTART;
1186 }
1187
1188 *rmpp = rmp;
1189 *rbnp = rbn;
1190
1191 jfs_info("xtSplitPage: sp:0x%p rp:0x%p", sp, rp);
1192 return rc;
1193
1194 clean_up:
1195
1196 /* Rollback quota allocation. */
1197 if (quota_allocation)
1198 vfs_dq_free_block(ip, quota_allocation);
1199
1200 return (rc);
1201 }
1202
1203
1204 /*
1205 * xtSplitRoot()
1206 *
1207 * function:
1208 * split the full root page into original/root/split page and new
1209 * right page
1210 * i.e., root remains fixed in tree anchor (inode) and the root is
1211 * copied to a single new right child page since root page <<
1212 * non-root page, and the split root page contains a single entry
1213 * for the new right child page.
1214 *
1215 * parameter:
1216 * int tid,
1217 * struct inode *ip,
1218 * struct xtsplit *split,
1219 * struct metapage **rmpp)
1220 *
1221 * return:
1222 * Pointer to page in which to insert or NULL on error.
1223 */
1224 static int
1225 xtSplitRoot(tid_t tid,
1226 struct inode *ip, struct xtsplit * split, struct metapage ** rmpp)
1227 {
1228 xtpage_t *sp;
1229 struct metapage *rmp;
1230 xtpage_t *rp;
1231 s64 rbn;
1232 int skip, nextindex;
1233 xad_t *xad;
1234 pxd_t *pxd;
1235 struct pxdlist *pxdlist;
1236 struct tlock *tlck;
1237 struct xtlock *xtlck;
1238
1239 sp = &JFS_IP(ip)->i_xtroot;
1240
1241 INCREMENT(xtStat.split);
1242
1243 /*
1244 * allocate a single (right) child page
1245 */
1246 pxdlist = split->pxdlist;
1247 pxd = &pxdlist->pxd[pxdlist->npxd];
1248 pxdlist->npxd++;
1249 rbn = addressPXD(pxd);
1250 rmp = get_metapage(ip, rbn, PSIZE, 1);
1251 if (rmp == NULL)
1252 return -EIO;
1253
1254 /* Allocate blocks to quota. */
1255 if (vfs_dq_alloc_block(ip, lengthPXD(pxd))) {
1256 release_metapage(rmp);
1257 return -EDQUOT;
1258 }
1259
1260 jfs_info("xtSplitRoot: ip:0x%p rmp:0x%p", ip, rmp);
1261
1262 /*
1263 * acquire a transaction lock on the new right page;
1264 *
1265 * action: new page;
1266 */
1267 BT_MARK_DIRTY(rmp, ip);
1268
1269 rp = (xtpage_t *) rmp->data;
1270 rp->header.flag =
1271 (sp->header.flag & BT_LEAF) ? BT_LEAF : BT_INTERNAL;
1272 rp->header.self = *pxd;
1273 rp->header.nextindex = cpu_to_le16(XTENTRYSTART);
1274 rp->header.maxentry = cpu_to_le16(PSIZE >> L2XTSLOTSIZE);
1275
1276 /* initialize sibling pointers */
1277 rp->header.next = 0;
1278 rp->header.prev = 0;
1279
1280 /*
1281 * copy the in-line root page into new right page extent
1282 */
1283 nextindex = le16_to_cpu(sp->header.maxentry);
1284 memmove(&rp->xad[XTENTRYSTART], &sp->xad[XTENTRYSTART],
1285 (nextindex - XTENTRYSTART) << L2XTSLOTSIZE);
1286
1287 /*
1288 * insert the new entry into the new right/child page
1289 * (skip index in the new right page will not change)
1290 */
1291 skip = split->index;
1292 /* if insert into middle, shift right remaining entries */
1293 if (skip != nextindex)
1294 memmove(&rp->xad[skip + 1], &rp->xad[skip],
1295 (nextindex - skip) * sizeof(xad_t));
1296
1297 xad = &rp->xad[skip];
1298 XT_PUTENTRY(xad, split->flag, split->off, split->len, split->addr);
1299
1300 /* update page header */
1301 rp->header.nextindex = cpu_to_le16(nextindex + 1);
1302
1303 if (!test_cflag(COMMIT_Nolink, ip)) {
1304 tlck = txLock(tid, ip, rmp, tlckXTREE | tlckNEW);
1305 xtlck = (struct xtlock *) & tlck->lock;
1306 xtlck->lwm.offset = XTENTRYSTART;
1307 xtlck->lwm.length = le16_to_cpu(rp->header.nextindex) -
1308 XTENTRYSTART;
1309 }
1310
1311 /*
1312 * reset the root
1313 *
1314 * init root with the single entry for the new right page
1315 * set the 1st entry offset to 0, which force the left-most key
1316 * at any level of the tree to be less than any search key.
1317 */
1318 /*
1319 * acquire a transaction lock on the root page (in-memory inode);
1320 *
1321 * action: root split;
1322 */
1323 BT_MARK_DIRTY(split->mp, ip);
1324
1325 xad = &sp->xad[XTENTRYSTART];
1326 XT_PUTENTRY(xad, XAD_NEW, 0, JFS_SBI(ip->i_sb)->nbperpage, rbn);
1327
1328 /* update page header of root */
1329 sp->header.flag &= ~BT_LEAF;
1330 sp->header.flag |= BT_INTERNAL;
1331
1332 sp->header.nextindex = cpu_to_le16(XTENTRYSTART + 1);
1333
1334 if (!test_cflag(COMMIT_Nolink, ip)) {
1335 tlck = txLock(tid, ip, split->mp, tlckXTREE | tlckGROW);
1336 xtlck = (struct xtlock *) & tlck->lock;
1337 xtlck->lwm.offset = XTENTRYSTART;
1338 xtlck->lwm.length = 1;
1339 }
1340
1341 *rmpp = rmp;
1342
1343 jfs_info("xtSplitRoot: sp:0x%p rp:0x%p", sp, rp);
1344 return 0;
1345 }
1346
1347
1348 /*
1349 * xtExtend()
1350 *
1351 * function: extend in-place;
1352 *
1353 * note: existing extent may or may not have been committed.
1354 * caller is responsible for pager buffer cache update, and
1355 * working block allocation map update;
1356 * update pmap: alloc whole extended extent;
1357 */
1358 int xtExtend(tid_t tid, /* transaction id */
1359 struct inode *ip, s64 xoff, /* delta extent offset */
1360 s32 xlen, /* delta extent length */
1361 int flag)
1362 {
1363 int rc = 0;
1364 int cmp;
1365 struct metapage *mp; /* meta-page buffer */
1366 xtpage_t *p; /* base B+-tree index page */
1367 s64 bn;
1368 int index, nextindex, len;
1369 struct btstack btstack; /* traverse stack */
1370 struct xtsplit split; /* split information */
1371 xad_t *xad;
1372 s64 xaddr;
1373 struct tlock *tlck;
1374 struct xtlock *xtlck = NULL;
1375
1376 jfs_info("xtExtend: nxoff:0x%lx nxlen:0x%x", (ulong) xoff, xlen);
1377
1378 /* there must exist extent to be extended */
1379 if ((rc = xtSearch(ip, xoff - 1, NULL, &cmp, &btstack, XT_INSERT)))
1380 return rc;
1381
1382 /* retrieve search result */
1383 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
1384
1385 if (cmp != 0) {
1386 XT_PUTPAGE(mp);
1387 jfs_error(ip->i_sb, "xtExtend: xtSearch did not find extent");
1388 return -EIO;
1389 }
1390
1391 /* extension must be contiguous */
1392 xad = &p->xad[index];
1393 if ((offsetXAD(xad) + lengthXAD(xad)) != xoff) {
1394 XT_PUTPAGE(mp);
1395 jfs_error(ip->i_sb, "xtExtend: extension is not contiguous");
1396 return -EIO;
1397 }
1398
1399 /*
1400 * acquire a transaction lock on the leaf page;
1401 *
1402 * action: xad insertion/extension;
1403 */
1404 BT_MARK_DIRTY(mp, ip);
1405 if (!test_cflag(COMMIT_Nolink, ip)) {
1406 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
1407 xtlck = (struct xtlock *) & tlck->lock;
1408 }
1409
1410 /* extend will overflow extent ? */
1411 xlen = lengthXAD(xad) + xlen;
1412 if ((len = xlen - MAXXLEN) <= 0)
1413 goto extendOld;
1414
1415 /*
1416 * extent overflow: insert entry for new extent
1417 */
1418 //insertNew:
1419 xoff = offsetXAD(xad) + MAXXLEN;
1420 xaddr = addressXAD(xad) + MAXXLEN;
1421 nextindex = le16_to_cpu(p->header.nextindex);
1422
1423 /*
1424 * if the leaf page is full, insert the new entry and
1425 * propagate up the router entry for the new page from split
1426 *
1427 * The xtSplitUp() will insert the entry and unpin the leaf page.
1428 */
1429 if (nextindex == le16_to_cpu(p->header.maxentry)) {
1430 /* xtSpliUp() unpins leaf pages */
1431 split.mp = mp;
1432 split.index = index + 1;
1433 split.flag = XAD_NEW;
1434 split.off = xoff; /* split offset */
1435 split.len = len;
1436 split.addr = xaddr;
1437 split.pxdlist = NULL;
1438 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
1439 return rc;
1440
1441 /* get back old page */
1442 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1443 if (rc)
1444 return rc;
1445 /*
1446 * if leaf root has been split, original root has been
1447 * copied to new child page, i.e., original entry now
1448 * resides on the new child page;
1449 */
1450 if (p->header.flag & BT_INTERNAL) {
1451 ASSERT(p->header.nextindex ==
1452 cpu_to_le16(XTENTRYSTART + 1));
1453 xad = &p->xad[XTENTRYSTART];
1454 bn = addressXAD(xad);
1455 XT_PUTPAGE(mp);
1456
1457 /* get new child page */
1458 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1459 if (rc)
1460 return rc;
1461
1462 BT_MARK_DIRTY(mp, ip);
1463 if (!test_cflag(COMMIT_Nolink, ip)) {
1464 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
1465 xtlck = (struct xtlock *) & tlck->lock;
1466 }
1467 }
1468 }
1469 /*
1470 * insert the new entry into the leaf page
1471 */
1472 else {
1473 /* insert the new entry: mark the entry NEW */
1474 xad = &p->xad[index + 1];
1475 XT_PUTENTRY(xad, XAD_NEW, xoff, len, xaddr);
1476
1477 /* advance next available entry index */
1478 le16_add_cpu(&p->header.nextindex, 1);
1479 }
1480
1481 /* get back old entry */
1482 xad = &p->xad[index];
1483 xlen = MAXXLEN;
1484
1485 /*
1486 * extend old extent
1487 */
1488 extendOld:
1489 XADlength(xad, xlen);
1490 if (!(xad->flag & XAD_NEW))
1491 xad->flag |= XAD_EXTENDED;
1492
1493 if (!test_cflag(COMMIT_Nolink, ip)) {
1494 xtlck->lwm.offset =
1495 (xtlck->lwm.offset) ? min(index,
1496 (int)xtlck->lwm.offset) : index;
1497 xtlck->lwm.length =
1498 le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
1499 }
1500
1501 /* unpin the leaf page */
1502 XT_PUTPAGE(mp);
1503
1504 return rc;
1505 }
1506
1507 #ifdef _NOTYET
1508 /*
1509 * xtTailgate()
1510 *
1511 * function: split existing 'tail' extent
1512 * (split offset >= start offset of tail extent), and
1513 * relocate and extend the split tail half;
1514 *
1515 * note: existing extent may or may not have been committed.
1516 * caller is responsible for pager buffer cache update, and
1517 * working block allocation map update;
1518 * update pmap: free old split tail extent, alloc new extent;
1519 */
1520 int xtTailgate(tid_t tid, /* transaction id */
1521 struct inode *ip, s64 xoff, /* split/new extent offset */
1522 s32 xlen, /* new extent length */
1523 s64 xaddr, /* new extent address */
1524 int flag)
1525 {
1526 int rc = 0;
1527 int cmp;
1528 struct metapage *mp; /* meta-page buffer */
1529 xtpage_t *p; /* base B+-tree index page */
1530 s64 bn;
1531 int index, nextindex, llen, rlen;
1532 struct btstack btstack; /* traverse stack */
1533 struct xtsplit split; /* split information */
1534 xad_t *xad;
1535 struct tlock *tlck;
1536 struct xtlock *xtlck = 0;
1537 struct tlock *mtlck;
1538 struct maplock *pxdlock;
1539
1540 /*
1541 printf("xtTailgate: nxoff:0x%lx nxlen:0x%x nxaddr:0x%lx\n",
1542 (ulong)xoff, xlen, (ulong)xaddr);
1543 */
1544
1545 /* there must exist extent to be tailgated */
1546 if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, XT_INSERT)))
1547 return rc;
1548
1549 /* retrieve search result */
1550 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
1551
1552 if (cmp != 0) {
1553 XT_PUTPAGE(mp);
1554 jfs_error(ip->i_sb, "xtTailgate: couldn't find extent");
1555 return -EIO;
1556 }
1557
1558 /* entry found must be last entry */
1559 nextindex = le16_to_cpu(p->header.nextindex);
1560 if (index != nextindex - 1) {
1561 XT_PUTPAGE(mp);
1562 jfs_error(ip->i_sb,
1563 "xtTailgate: the entry found is not the last entry");
1564 return -EIO;
1565 }
1566
1567 BT_MARK_DIRTY(mp, ip);
1568 /*
1569 * acquire tlock of the leaf page containing original entry
1570 */
1571 if (!test_cflag(COMMIT_Nolink, ip)) {
1572 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
1573 xtlck = (struct xtlock *) & tlck->lock;
1574 }
1575
1576 /* completely replace extent ? */
1577 xad = &p->xad[index];
1578 /*
1579 printf("xtTailgate: xoff:0x%lx xlen:0x%x xaddr:0x%lx\n",
1580 (ulong)offsetXAD(xad), lengthXAD(xad), (ulong)addressXAD(xad));
1581 */
1582 if ((llen = xoff - offsetXAD(xad)) == 0)
1583 goto updateOld;
1584
1585 /*
1586 * partially replace extent: insert entry for new extent
1587 */
1588 //insertNew:
1589 /*
1590 * if the leaf page is full, insert the new entry and
1591 * propagate up the router entry for the new page from split
1592 *
1593 * The xtSplitUp() will insert the entry and unpin the leaf page.
1594 */
1595 if (nextindex == le16_to_cpu(p->header.maxentry)) {
1596 /* xtSpliUp() unpins leaf pages */
1597 split.mp = mp;
1598 split.index = index + 1;
1599 split.flag = XAD_NEW;
1600 split.off = xoff; /* split offset */
1601 split.len = xlen;
1602 split.addr = xaddr;
1603 split.pxdlist = NULL;
1604 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
1605 return rc;
1606
1607 /* get back old page */
1608 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1609 if (rc)
1610 return rc;
1611 /*
1612 * if leaf root has been split, original root has been
1613 * copied to new child page, i.e., original entry now
1614 * resides on the new child page;
1615 */
1616 if (p->header.flag & BT_INTERNAL) {
1617 ASSERT(p->header.nextindex ==
1618 cpu_to_le16(XTENTRYSTART + 1));
1619 xad = &p->xad[XTENTRYSTART];
1620 bn = addressXAD(xad);
1621 XT_PUTPAGE(mp);
1622
1623 /* get new child page */
1624 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1625 if (rc)
1626 return rc;
1627
1628 BT_MARK_DIRTY(mp, ip);
1629 if (!test_cflag(COMMIT_Nolink, ip)) {
1630 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
1631 xtlck = (struct xtlock *) & tlck->lock;
1632 }
1633 }
1634 }
1635 /*
1636 * insert the new entry into the leaf page
1637 */
1638 else {
1639 /* insert the new entry: mark the entry NEW */
1640 xad = &p->xad[index + 1];
1641 XT_PUTENTRY(xad, XAD_NEW, xoff, xlen, xaddr);
1642
1643 /* advance next available entry index */
1644 le16_add_cpu(&p->header.nextindex, 1);
1645 }
1646
1647 /* get back old XAD */
1648 xad = &p->xad[index];
1649
1650 /*
1651 * truncate/relocate old extent at split offset
1652 */
1653 updateOld:
1654 /* update dmap for old/committed/truncated extent */
1655 rlen = lengthXAD(xad) - llen;
1656 if (!(xad->flag & XAD_NEW)) {
1657 /* free from PWMAP at commit */
1658 if (!test_cflag(COMMIT_Nolink, ip)) {
1659 mtlck = txMaplock(tid, ip, tlckMAP);
1660 pxdlock = (struct maplock *) & mtlck->lock;
1661 pxdlock->flag = mlckFREEPXD;
1662 PXDaddress(&pxdlock->pxd, addressXAD(xad) + llen);
1663 PXDlength(&pxdlock->pxd, rlen);
1664 pxdlock->index = 1;
1665 }
1666 } else
1667 /* free from WMAP */
1668 dbFree(ip, addressXAD(xad) + llen, (s64) rlen);
1669
1670 if (llen)
1671 /* truncate */
1672 XADlength(xad, llen);
1673 else
1674 /* replace */
1675 XT_PUTENTRY(xad, XAD_NEW, xoff, xlen, xaddr);
1676
1677 if (!test_cflag(COMMIT_Nolink, ip)) {
1678 xtlck->lwm.offset = (xtlck->lwm.offset) ?
1679 min(index, (int)xtlck->lwm.offset) : index;
1680 xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
1681 xtlck->lwm.offset;
1682 }
1683
1684 /* unpin the leaf page */
1685 XT_PUTPAGE(mp);
1686
1687 return rc;
1688 }
1689 #endif /* _NOTYET */
1690
1691 /*
1692 * xtUpdate()
1693 *
1694 * function: update XAD;
1695 *
1696 * update extent for allocated_but_not_recorded or
1697 * compressed extent;
1698 *
1699 * parameter:
1700 * nxad - new XAD;
1701 * logical extent of the specified XAD must be completely
1702 * contained by an existing XAD;
1703 */
1704 int xtUpdate(tid_t tid, struct inode *ip, xad_t * nxad)
1705 { /* new XAD */
1706 int rc = 0;
1707 int cmp;
1708 struct metapage *mp; /* meta-page buffer */
1709 xtpage_t *p; /* base B+-tree index page */
1710 s64 bn;
1711 int index0, index, newindex, nextindex;
1712 struct btstack btstack; /* traverse stack */
1713 struct xtsplit split; /* split information */
1714 xad_t *xad, *lxad, *rxad;
1715 int xflag;
1716 s64 nxoff, xoff;
1717 int nxlen, xlen, lxlen, rxlen;
1718 s64 nxaddr, xaddr;
1719 struct tlock *tlck;
1720 struct xtlock *xtlck = NULL;
1721 int newpage = 0;
1722
1723 /* there must exist extent to be tailgated */
1724 nxoff = offsetXAD(nxad);
1725 nxlen = lengthXAD(nxad);
1726 nxaddr = addressXAD(nxad);
1727
1728 if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
1729 return rc;
1730
1731 /* retrieve search result */
1732 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index0);
1733
1734 if (cmp != 0) {
1735 XT_PUTPAGE(mp);
1736 jfs_error(ip->i_sb, "xtUpdate: Could not find extent");
1737 return -EIO;
1738 }
1739
1740 BT_MARK_DIRTY(mp, ip);
1741 /*
1742 * acquire tlock of the leaf page containing original entry
1743 */
1744 if (!test_cflag(COMMIT_Nolink, ip)) {
1745 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
1746 xtlck = (struct xtlock *) & tlck->lock;
1747 }
1748
1749 xad = &p->xad[index0];
1750 xflag = xad->flag;
1751 xoff = offsetXAD(xad);
1752 xlen = lengthXAD(xad);
1753 xaddr = addressXAD(xad);
1754
1755 /* nXAD must be completely contained within XAD */
1756 if ((xoff > nxoff) ||
1757 (nxoff + nxlen > xoff + xlen)) {
1758 XT_PUTPAGE(mp);
1759 jfs_error(ip->i_sb,
1760 "xtUpdate: nXAD in not completely contained within XAD");
1761 return -EIO;
1762 }
1763
1764 index = index0;
1765 newindex = index + 1;
1766 nextindex = le16_to_cpu(p->header.nextindex);
1767
1768 #ifdef _JFS_WIP_NOCOALESCE
1769 if (xoff < nxoff)
1770 goto updateRight;
1771
1772 /*
1773 * replace XAD with nXAD
1774 */
1775 replace: /* (nxoff == xoff) */
1776 if (nxlen == xlen) {
1777 /* replace XAD with nXAD:recorded */
1778 *xad = *nxad;
1779 xad->flag = xflag & ~XAD_NOTRECORDED;
1780
1781 goto out;
1782 } else /* (nxlen < xlen) */
1783 goto updateLeft;
1784 #endif /* _JFS_WIP_NOCOALESCE */
1785
1786 /* #ifdef _JFS_WIP_COALESCE */
1787 if (xoff < nxoff)
1788 goto coalesceRight;
1789
1790 /*
1791 * coalesce with left XAD
1792 */
1793 //coalesceLeft: /* (xoff == nxoff) */
1794 /* is XAD first entry of page ? */
1795 if (index == XTENTRYSTART)
1796 goto replace;
1797
1798 /* is nXAD logically and physically contiguous with lXAD ? */
1799 lxad = &p->xad[index - 1];
1800 lxlen = lengthXAD(lxad);
1801 if (!(lxad->flag & XAD_NOTRECORDED) &&
1802 (nxoff == offsetXAD(lxad) + lxlen) &&
1803 (nxaddr == addressXAD(lxad) + lxlen) &&
1804 (lxlen + nxlen < MAXXLEN)) {
1805 /* extend right lXAD */
1806 index0 = index - 1;
1807 XADlength(lxad, lxlen + nxlen);
1808
1809 /* If we just merged two extents together, need to make sure the
1810 * right extent gets logged. If the left one is marked XAD_NEW,
1811 * then we know it will be logged. Otherwise, mark as
1812 * XAD_EXTENDED
1813 */
1814 if (!(lxad->flag & XAD_NEW))
1815 lxad->flag |= XAD_EXTENDED;
1816
1817 if (xlen > nxlen) {
1818 /* truncate XAD */
1819 XADoffset(xad, xoff + nxlen);
1820 XADlength(xad, xlen - nxlen);
1821 XADaddress(xad, xaddr + nxlen);
1822 goto out;
1823 } else { /* (xlen == nxlen) */
1824
1825 /* remove XAD */
1826 if (index < nextindex - 1)
1827 memmove(&p->xad[index], &p->xad[index + 1],
1828 (nextindex - index -
1829 1) << L2XTSLOTSIZE);
1830
1831 p->header.nextindex =
1832 cpu_to_le16(le16_to_cpu(p->header.nextindex) -
1833 1);
1834
1835 index = index0;
1836 newindex = index + 1;
1837 nextindex = le16_to_cpu(p->header.nextindex);
1838 xoff = nxoff = offsetXAD(lxad);
1839 xlen = nxlen = lxlen + nxlen;
1840 xaddr = nxaddr = addressXAD(lxad);
1841 goto coalesceRight;
1842 }
1843 }
1844
1845 /*
1846 * replace XAD with nXAD
1847 */
1848 replace: /* (nxoff == xoff) */
1849 if (nxlen == xlen) {
1850 /* replace XAD with nXAD:recorded */
1851 *xad = *nxad;
1852 xad->flag = xflag & ~XAD_NOTRECORDED;
1853
1854 goto coalesceRight;
1855 } else /* (nxlen < xlen) */
1856 goto updateLeft;
1857
1858 /*
1859 * coalesce with right XAD
1860 */
1861 coalesceRight: /* (xoff <= nxoff) */
1862 /* is XAD last entry of page ? */
1863 if (newindex == nextindex) {
1864 if (xoff == nxoff)
1865 goto out;
1866 goto updateRight;
1867 }
1868
1869 /* is nXAD logically and physically contiguous with rXAD ? */
1870 rxad = &p->xad[index + 1];
1871 rxlen = lengthXAD(rxad);
1872 if (!(rxad->flag & XAD_NOTRECORDED) &&
1873 (nxoff + nxlen == offsetXAD(rxad)) &&
1874 (nxaddr + nxlen == addressXAD(rxad)) &&
1875 (rxlen + nxlen < MAXXLEN)) {
1876 /* extend left rXAD */
1877 XADoffset(rxad, nxoff);
1878 XADlength(rxad, rxlen + nxlen);
1879 XADaddress(rxad, nxaddr);
1880
1881 /* If we just merged two extents together, need to make sure
1882 * the left extent gets logged. If the right one is marked
1883 * XAD_NEW, then we know it will be logged. Otherwise, mark as
1884 * XAD_EXTENDED
1885 */
1886 if (!(rxad->flag & XAD_NEW))
1887 rxad->flag |= XAD_EXTENDED;
1888
1889 if (xlen > nxlen)
1890 /* truncate XAD */
1891 XADlength(xad, xlen - nxlen);
1892 else { /* (xlen == nxlen) */
1893
1894 /* remove XAD */
1895 memmove(&p->xad[index], &p->xad[index + 1],
1896 (nextindex - index - 1) << L2XTSLOTSIZE);
1897
1898 p->header.nextindex =
1899 cpu_to_le16(le16_to_cpu(p->header.nextindex) -
1900 1);
1901 }
1902
1903 goto out;
1904 } else if (xoff == nxoff)
1905 goto out;
1906
1907 if (xoff >= nxoff) {
1908 XT_PUTPAGE(mp);
1909 jfs_error(ip->i_sb, "xtUpdate: xoff >= nxoff");
1910 return -EIO;
1911 }
1912 /* #endif _JFS_WIP_COALESCE */
1913
1914 /*
1915 * split XAD into (lXAD, nXAD):
1916 *
1917 * |---nXAD--->
1918 * --|----------XAD----------|--
1919 * |-lXAD-|
1920 */
1921 updateRight: /* (xoff < nxoff) */
1922 /* truncate old XAD as lXAD:not_recorded */
1923 xad = &p->xad[index];
1924 XADlength(xad, nxoff - xoff);
1925
1926 /* insert nXAD:recorded */
1927 if (nextindex == le16_to_cpu(p->header.maxentry)) {
1928
1929 /* xtSpliUp() unpins leaf pages */
1930 split.mp = mp;
1931 split.index = newindex;
1932 split.flag = xflag & ~XAD_NOTRECORDED;
1933 split.off = nxoff;
1934 split.len = nxlen;
1935 split.addr = nxaddr;
1936 split.pxdlist = NULL;
1937 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
1938 return rc;
1939
1940 /* get back old page */
1941 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1942 if (rc)
1943 return rc;
1944 /*
1945 * if leaf root has been split, original root has been
1946 * copied to new child page, i.e., original entry now
1947 * resides on the new child page;
1948 */
1949 if (p->header.flag & BT_INTERNAL) {
1950 ASSERT(p->header.nextindex ==
1951 cpu_to_le16(XTENTRYSTART + 1));
1952 xad = &p->xad[XTENTRYSTART];
1953 bn = addressXAD(xad);
1954 XT_PUTPAGE(mp);
1955
1956 /* get new child page */
1957 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1958 if (rc)
1959 return rc;
1960
1961 BT_MARK_DIRTY(mp, ip);
1962 if (!test_cflag(COMMIT_Nolink, ip)) {
1963 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
1964 xtlck = (struct xtlock *) & tlck->lock;
1965 }
1966 } else {
1967 /* is nXAD on new page ? */
1968 if (newindex >
1969 (le16_to_cpu(p->header.maxentry) >> 1)) {
1970 newindex =
1971 newindex -
1972 le16_to_cpu(p->header.nextindex) +
1973 XTENTRYSTART;
1974 newpage = 1;
1975 }
1976 }
1977 } else {
1978 /* if insert into middle, shift right remaining entries */
1979 if (newindex < nextindex)
1980 memmove(&p->xad[newindex + 1], &p->xad[newindex],
1981 (nextindex - newindex) << L2XTSLOTSIZE);
1982
1983 /* insert the entry */
1984 xad = &p->xad[newindex];
1985 *xad = *nxad;
1986 xad->flag = xflag & ~XAD_NOTRECORDED;
1987
1988 /* advance next available entry index. */
1989 p->header.nextindex =
1990 cpu_to_le16(le16_to_cpu(p->header.nextindex) + 1);
1991 }
1992
1993 /*
1994 * does nXAD force 3-way split ?
1995 *
1996 * |---nXAD--->|
1997 * --|----------XAD-------------|--
1998 * |-lXAD-| |-rXAD -|
1999 */
2000 if (nxoff + nxlen == xoff + xlen)
2001 goto out;
2002
2003 /* reorient nXAD as XAD for further split XAD into (nXAD, rXAD) */
2004 if (newpage) {
2005 /* close out old page */
2006 if (!test_cflag(COMMIT_Nolink, ip)) {
2007 xtlck->lwm.offset = (xtlck->lwm.offset) ?
2008 min(index0, (int)xtlck->lwm.offset) : index0;
2009 xtlck->lwm.length =
2010 le16_to_cpu(p->header.nextindex) -
2011 xtlck->lwm.offset;
2012 }
2013
2014 bn = le64_to_cpu(p->header.next);
2015 XT_PUTPAGE(mp);
2016
2017 /* get new right page */
2018 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2019 if (rc)
2020 return rc;
2021
2022 BT_MARK_DIRTY(mp, ip);
2023 if (!test_cflag(COMMIT_Nolink, ip)) {
2024 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
2025 xtlck = (struct xtlock *) & tlck->lock;
2026 }
2027
2028 index0 = index = newindex;
2029 } else
2030 index++;
2031
2032 newindex = index + 1;
2033 nextindex = le16_to_cpu(p->header.nextindex);
2034 xlen = xlen - (nxoff - xoff);
2035 xoff = nxoff;
2036 xaddr = nxaddr;
2037
2038 /* recompute split pages */
2039 if (nextindex == le16_to_cpu(p->header.maxentry)) {
2040 XT_PUTPAGE(mp);
2041
2042 if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
2043 return rc;
2044
2045 /* retrieve search result */
2046 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index0);
2047
2048 if (cmp != 0) {
2049 XT_PUTPAGE(mp);
2050 jfs_error(ip->i_sb, "xtUpdate: xtSearch failed");
2051 return -EIO;
2052 }
2053
2054 if (index0 != index) {
2055 XT_PUTPAGE(mp);
2056 jfs_error(ip->i_sb,
2057 "xtUpdate: unexpected value of index");
2058 return -EIO;
2059 }
2060 }
2061
2062 /*
2063 * split XAD into (nXAD, rXAD)
2064 *
2065 * ---nXAD---|
2066 * --|----------XAD----------|--
2067 * |-rXAD-|
2068 */
2069 updateLeft: /* (nxoff == xoff) && (nxlen < xlen) */
2070 /* update old XAD with nXAD:recorded */
2071 xad = &p->xad[index];
2072 *xad = *nxad;
2073 xad->flag = xflag & ~XAD_NOTRECORDED;
2074
2075 /* insert rXAD:not_recorded */
2076 xoff = xoff + nxlen;
2077 xlen = xlen - nxlen;
2078 xaddr = xaddr + nxlen;
2079 if (nextindex == le16_to_cpu(p->header.maxentry)) {
2080 /*
2081 printf("xtUpdate.updateLeft.split p:0x%p\n", p);
2082 */
2083 /* xtSpliUp() unpins leaf pages */
2084 split.mp = mp;
2085 split.index = newindex;
2086 split.flag = xflag;
2087 split.off = xoff;
2088 split.len = xlen;
2089 split.addr = xaddr;
2090 split.pxdlist = NULL;
2091 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
2092 return rc;
2093
2094 /* get back old page */
2095 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2096 if (rc)
2097 return rc;
2098
2099 /*
2100 * if leaf root has been split, original root has been
2101 * copied to new child page, i.e., original entry now
2102 * resides on the new child page;
2103 */
2104 if (p->header.flag & BT_INTERNAL) {
2105 ASSERT(p->header.nextindex ==
2106 cpu_to_le16(XTENTRYSTART + 1));
2107 xad = &p->xad[XTENTRYSTART];
2108 bn = addressXAD(xad);
2109 XT_PUTPAGE(mp);
2110
2111 /* get new child page */
2112 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2113 if (rc)
2114 return rc;
2115
2116 BT_MARK_DIRTY(mp, ip);
2117 if (!test_cflag(COMMIT_Nolink, ip)) {
2118 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
2119 xtlck = (struct xtlock *) & tlck->lock;
2120 }
2121 }
2122 } else {
2123 /* if insert into middle, shift right remaining entries */
2124 if (newindex < nextindex)
2125 memmove(&p->xad[newindex + 1], &p->xad[newindex],
2126 (nextindex - newindex) << L2XTSLOTSIZE);
2127
2128 /* insert the entry */
2129 xad = &p->xad[newindex];
2130 XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
2131
2132 /* advance next available entry index. */
2133 p->header.nextindex =
2134 cpu_to_le16(le16_to_cpu(p->header.nextindex) + 1);
2135 }
2136
2137 out:
2138 if (!test_cflag(COMMIT_Nolink, ip)) {
2139 xtlck->lwm.offset = (xtlck->lwm.offset) ?
2140 min(index0, (int)xtlck->lwm.offset) : index0;
2141 xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
2142 xtlck->lwm.offset;
2143 }
2144
2145 /* unpin the leaf page */
2146 XT_PUTPAGE(mp);
2147
2148 return rc;
2149 }
2150
2151
2152 /*
2153 * xtAppend()
2154 *
2155 * function: grow in append mode from contiguous region specified ;
2156 *
2157 * parameter:
2158 * tid - transaction id;
2159 * ip - file object;
2160 * xflag - extent flag:
2161 * xoff - extent offset;
2162 * maxblocks - max extent length;
2163 * xlen - extent length (in/out);
2164 * xaddrp - extent address pointer (in/out):
2165 * flag -
2166 *
2167 * return:
2168 */
2169 int xtAppend(tid_t tid, /* transaction id */
2170 struct inode *ip, int xflag, s64 xoff, s32 maxblocks,
2171 s32 * xlenp, /* (in/out) */
2172 s64 * xaddrp, /* (in/out) */
2173 int flag)
2174 {
2175 int rc = 0;
2176 struct metapage *mp; /* meta-page buffer */
2177 xtpage_t *p; /* base B+-tree index page */
2178 s64 bn, xaddr;
2179 int index, nextindex;
2180 struct btstack btstack; /* traverse stack */
2181 struct xtsplit split; /* split information */
2182 xad_t *xad;
2183 int cmp;
2184 struct tlock *tlck;
2185 struct xtlock *xtlck;
2186 int nsplit, nblocks, xlen;
2187 struct pxdlist pxdlist;
2188 pxd_t *pxd;
2189 s64 next;
2190
2191 xaddr = *xaddrp;
2192 xlen = *xlenp;
2193 jfs_info("xtAppend: xoff:0x%lx maxblocks:%d xlen:%d xaddr:0x%lx",
2194 (ulong) xoff, maxblocks, xlen, (ulong) xaddr);
2195
2196 /*
2197 * search for the entry location at which to insert:
2198 *
2199 * xtFastSearch() and xtSearch() both returns (leaf page
2200 * pinned, index at which to insert).
2201 * n.b. xtSearch() may return index of maxentry of
2202 * the full page.
2203 */
2204 if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
2205 return rc;
2206
2207 /* retrieve search result */
2208 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
2209
2210 if (cmp == 0) {
2211 rc = -EEXIST;
2212 goto out;
2213 }
2214
2215 if (next)
2216 xlen = min(xlen, (int)(next - xoff));
2217 //insert:
2218 /*
2219 * insert entry for new extent
2220 */
2221 xflag |= XAD_NEW;
2222
2223 /*
2224 * if the leaf page is full, split the page and
2225 * propagate up the router entry for the new page from split
2226 *
2227 * The xtSplitUp() will insert the entry and unpin the leaf page.
2228 */
2229 nextindex = le16_to_cpu(p->header.nextindex);
2230 if (nextindex < le16_to_cpu(p->header.maxentry))
2231 goto insertLeaf;
2232
2233 /*
2234 * allocate new index blocks to cover index page split(s)
2235 */
2236 nsplit = btstack.nsplit;
2237 split.pxdlist = &pxdlist;
2238 pxdlist.maxnpxd = pxdlist.npxd = 0;
2239 pxd = &pxdlist.pxd[0];
2240 nblocks = JFS_SBI(ip->i_sb)->nbperpage;
2241 for (; nsplit > 0; nsplit--, pxd++, xaddr += nblocks, maxblocks -= nblocks) {
2242 if ((rc = dbAllocBottomUp(ip, xaddr, (s64) nblocks)) == 0) {
2243 PXDaddress(pxd, xaddr);
2244 PXDlength(pxd, nblocks);
2245
2246 pxdlist.maxnpxd++;
2247
2248 continue;
2249 }
2250
2251 /* undo allocation */
2252
2253 goto out;
2254 }
2255
2256 xlen = min(xlen, maxblocks);
2257
2258 /*
2259 * allocate data extent requested
2260 */
2261 if ((rc = dbAllocBottomUp(ip, xaddr, (s64) xlen)))
2262 goto out;
2263
2264 split.mp = mp;
2265 split.index = index;
2266 split.flag = xflag;
2267 split.off = xoff;
2268 split.len = xlen;
2269 split.addr = xaddr;
2270 if ((rc = xtSplitUp(tid, ip, &split, &btstack))) {
2271 /* undo data extent allocation */
2272 dbFree(ip, *xaddrp, (s64) * xlenp);
2273
2274 return rc;
2275 }
2276
2277 *xaddrp = xaddr;
2278 *xlenp = xlen;
2279 return 0;
2280
2281 /*
2282 * insert the new entry into the leaf page
2283 */
2284 insertLeaf:
2285 /*
2286 * allocate data extent requested
2287 */
2288 if ((rc = dbAllocBottomUp(ip, xaddr, (s64) xlen)))
2289 goto out;
2290
2291 BT_MARK_DIRTY(mp, ip);
2292 /*
2293 * acquire a transaction lock on the leaf page;
2294 *
2295 * action: xad insertion/extension;
2296 */
2297 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
2298 xtlck = (struct xtlock *) & tlck->lock;
2299
2300 /* insert the new entry: mark the entry NEW */
2301 xad = &p->xad[index];
2302 XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
2303
2304 /* advance next available entry index */
2305 le16_add_cpu(&p->header.nextindex, 1);
2306
2307 xtlck->lwm.offset =
2308 (xtlck->lwm.offset) ? min(index,(int) xtlck->lwm.offset) : index;
2309 xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
2310 xtlck->lwm.offset;
2311
2312 *xaddrp = xaddr;
2313 *xlenp = xlen;
2314
2315 out:
2316 /* unpin the leaf page */
2317 XT_PUTPAGE(mp);
2318
2319 return rc;
2320 }
2321 #ifdef _STILL_TO_PORT
2322
2323 /* - TBD for defragmentaion/reorganization -
2324 *
2325 * xtDelete()
2326 *
2327 * function:
2328 * delete the entry with the specified key.
2329 *
2330 * N.B.: whole extent of the entry is assumed to be deleted.
2331 *
2332 * parameter:
2333 *
2334 * return:
2335 * ENOENT: if the entry is not found.
2336 *
2337 * exception:
2338 */
2339 int xtDelete(tid_t tid, struct inode *ip, s64 xoff, s32 xlen, int flag)
2340 {
2341 int rc = 0;
2342 struct btstack btstack;
2343 int cmp;
2344 s64 bn;
2345 struct metapage *mp;
2346 xtpage_t *p;
2347 int index, nextindex;
2348 struct tlock *tlck;
2349 struct xtlock *xtlck;
2350
2351 /*
2352 * find the matching entry; xtSearch() pins the page
2353 */
2354 if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
2355 return rc;
2356
2357 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
2358 if (cmp) {
2359 /* unpin the leaf page */
2360 XT_PUTPAGE(mp);
2361 return -ENOENT;
2362 }
2363
2364 /*
2365 * delete the entry from the leaf page
2366 */
2367 nextindex = le16_to_cpu(p->header.nextindex);
2368 le16_add_cpu(&p->header.nextindex, -1);
2369
2370 /*
2371 * if the leaf page bocome empty, free the page
2372 */
2373 if (p->header.nextindex == cpu_to_le16(XTENTRYSTART))
2374 return (xtDeleteUp(tid, ip, mp, p, &btstack));
2375
2376 BT_MARK_DIRTY(mp, ip);
2377 /*
2378 * acquire a transaction lock on the leaf page;
2379 *
2380 * action:xad deletion;
2381 */
2382 tlck = txLock(tid, ip, mp, tlckXTREE);
2383 xtlck = (struct xtlock *) & tlck->lock;
2384 xtlck->lwm.offset =
2385 (xtlck->lwm.offset) ? min(index, xtlck->lwm.offset) : index;
2386
2387 /* if delete from middle, shift left/compact the remaining entries */
2388 if (index < nextindex - 1)
2389 memmove(&p->xad[index], &p->xad[index + 1],
2390 (nextindex - index - 1) * sizeof(xad_t));
2391
2392 XT_PUTPAGE(mp);
2393
2394 return 0;
2395 }
2396
2397
2398 /* - TBD for defragmentaion/reorganization -
2399 *
2400 * xtDeleteUp()
2401 *
2402 * function:
2403 * free empty pages as propagating deletion up the tree
2404 *
2405 * parameter:
2406 *
2407 * return:
2408 */
2409 static int
2410 xtDeleteUp(tid_t tid, struct inode *ip,
2411 struct metapage * fmp, xtpage_t * fp, struct btstack * btstack)
2412 {
2413 int rc = 0;
2414 struct metapage *mp;
2415 xtpage_t *p;
2416 int index, nextindex;
2417 s64 xaddr;
2418 int xlen;
2419 struct btframe *parent;
2420 struct tlock *tlck;
2421 struct xtlock *xtlck;
2422
2423 /*
2424 * keep root leaf page which has become empty
2425 */
2426 if (fp->header.flag & BT_ROOT) {
2427 /* keep the root page */
2428 fp->header.flag &= ~BT_INTERNAL;
2429 fp->header.flag |= BT_LEAF;
2430 fp->header.nextindex = cpu_to_le16(XTENTRYSTART);
2431
2432 /* XT_PUTPAGE(fmp); */
2433
2434 return 0;
2435 }
2436
2437 /*
2438 * free non-root leaf page
2439 */
2440 if ((rc = xtRelink(tid, ip, fp))) {
2441 XT_PUTPAGE(fmp);
2442 return rc;
2443 }
2444
2445 xaddr = addressPXD(&fp->header.self);
2446 xlen = lengthPXD(&fp->header.self);
2447 /* free the page extent */
2448 dbFree(ip, xaddr, (s64) xlen);
2449
2450 /* free the buffer page */
2451 discard_metapage(fmp);
2452
2453 /*
2454 * propagate page deletion up the index tree
2455 *
2456 * If the delete from the parent page makes it empty,
2457 * continue all the way up the tree.
2458 * stop if the root page is reached (which is never deleted) or
2459 * if the entry deletion does not empty the page.
2460 */
2461 while ((parent = BT_POP(btstack)) != NULL) {
2462 /* get/pin the parent page <sp> */
2463 XT_GETPAGE(ip, parent->bn, mp, PSIZE, p, rc);
2464 if (rc)
2465 return rc;
2466
2467 index = parent->index;
2468
2469 /* delete the entry for the freed child page from parent.
2470 */
2471 nextindex = le16_to_cpu(p->header.nextindex);
2472
2473 /*
2474 * the parent has the single entry being deleted:
2475 * free the parent page which has become empty.
2476 */
2477 if (nextindex == 1) {
2478 if (p->header.flag & BT_ROOT) {
2479 /* keep the root page */
2480 p->header.flag &= ~BT_INTERNAL;
2481 p->header.flag |= BT_LEAF;
2482 p->header.nextindex =
2483 cpu_to_le16(XTENTRYSTART);
2484
2485 /* XT_PUTPAGE(mp); */
2486
2487 break;
2488 } else {
2489 /* free the parent page */
2490 if ((rc = xtRelink(tid, ip, p)))
2491 return rc;
2492
2493 xaddr = addressPXD(&p->header.self);
2494 /* free the page extent */
2495 dbFree(ip, xaddr,
2496 (s64) JFS_SBI(ip->i_sb)->nbperpage);
2497
2498 /* unpin/free the buffer page */
2499 discard_metapage(mp);
2500
2501 /* propagate up */
2502 continue;
2503 }
2504 }
2505 /*
2506 * the parent has other entries remaining:
2507 * delete the router entry from the parent page.
2508 */
2509 else {
2510 BT_MARK_DIRTY(mp, ip);
2511 /*
2512 * acquire a transaction lock on the leaf page;
2513 *
2514 * action:xad deletion;
2515 */
2516 tlck = txLock(tid, ip, mp, tlckXTREE);
2517 xtlck = (struct xtlock *) & tlck->lock;
2518 xtlck->lwm.offset =
2519 (xtlck->lwm.offset) ? min(index,
2520 xtlck->lwm.
2521 offset) : index;
2522
2523 /* if delete from middle,
2524 * shift left/compact the remaining entries in the page
2525 */
2526 if (index < nextindex - 1)
2527 memmove(&p->xad[index], &p->xad[index + 1],
2528 (nextindex - index -
2529 1) << L2XTSLOTSIZE);
2530
2531 le16_add_cpu(&p->header.nextindex, -1);
2532 jfs_info("xtDeleteUp(entry): 0x%lx[%d]",
2533 (ulong) parent->bn, index);
2534 }
2535
2536 /* unpin the parent page */
2537 XT_PUTPAGE(mp);
2538
2539 /* exit propagation up */
2540 break;
2541 }
2542
2543 return 0;
2544 }
2545
2546
2547 /*
2548 * NAME: xtRelocate()
2549 *
2550 * FUNCTION: relocate xtpage or data extent of regular file;
2551 * This function is mainly used by defragfs utility.
2552 *
2553 * NOTE: This routine does not have the logic to handle
2554 * uncommitted allocated extent. The caller should call
2555 * txCommit() to commit all the allocation before call
2556 * this routine.
2557 */
2558 int
2559 xtRelocate(tid_t tid, struct inode * ip, xad_t * oxad, /* old XAD */
2560 s64 nxaddr, /* new xaddr */
2561 int xtype)
2562 { /* extent type: XTPAGE or DATAEXT */
2563 int rc = 0;
2564 struct tblock *tblk;
2565 struct tlock *tlck;
2566 struct xtlock *xtlck;
2567 struct metapage *mp, *pmp, *lmp, *rmp; /* meta-page buffer */
2568 xtpage_t *p, *pp, *rp, *lp; /* base B+-tree index page */
2569 xad_t *xad;
2570 pxd_t *pxd;
2571 s64 xoff, xsize;
2572 int xlen;
2573 s64 oxaddr, sxaddr, dxaddr, nextbn, prevbn;
2574 cbuf_t *cp;
2575 s64 offset, nbytes, nbrd, pno;
2576 int nb, npages, nblks;
2577 s64 bn;
2578 int cmp;
2579 int index;
2580 struct pxd_lock *pxdlock;
2581 struct btstack btstack; /* traverse stack */
2582
2583 xtype = xtype & EXTENT_TYPE;
2584
2585 xoff = offsetXAD(oxad);
2586 oxaddr = addressXAD(oxad);
2587 xlen = lengthXAD(oxad);
2588
2589 /* validate extent offset */
2590 offset = xoff << JFS_SBI(ip->i_sb)->l2bsize;
2591 if (offset >= ip->i_size)
2592 return -ESTALE; /* stale extent */
2593
2594 jfs_info("xtRelocate: xtype:%d xoff:0x%lx xlen:0x%x xaddr:0x%lx:0x%lx",
2595 xtype, (ulong) xoff, xlen, (ulong) oxaddr, (ulong) nxaddr);
2596
2597 /*
2598 * 1. get and validate the parent xtpage/xad entry
2599 * covering the source extent to be relocated;
2600 */
2601 if (xtype == DATAEXT) {
2602 /* search in leaf entry */
2603 rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
2604 if (rc)
2605 return rc;
2606
2607 /* retrieve search result */
2608 XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2609
2610 if (cmp) {
2611 XT_PUTPAGE(pmp);
2612 return -ESTALE;
2613 }
2614
2615 /* validate for exact match with a single entry */
2616 xad = &pp->xad[index];
2617 if (addressXAD(xad) != oxaddr || lengthXAD(xad) != xlen) {
2618 XT_PUTPAGE(pmp);
2619 return -ESTALE;
2620 }
2621 } else { /* (xtype == XTPAGE) */
2622
2623 /* search in internal entry */
2624 rc = xtSearchNode(ip, oxad, &cmp, &btstack, 0);
2625 if (rc)
2626 return rc;
2627
2628 /* retrieve search result */
2629 XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2630
2631 if (cmp) {
2632 XT_PUTPAGE(pmp);
2633 return -ESTALE;
2634 }
2635
2636 /* xtSearchNode() validated for exact match with a single entry
2637 */
2638 xad = &pp->xad[index];
2639 }
2640 jfs_info("xtRelocate: parent xad entry validated.");
2641
2642 /*
2643 * 2. relocate the extent
2644 */
2645 if (xtype == DATAEXT) {
2646 /* if the extent is allocated-but-not-recorded
2647 * there is no real data to be moved in this extent,
2648 */
2649 if (xad->flag & XAD_NOTRECORDED)
2650 goto out;
2651 else
2652 /* release xtpage for cmRead()/xtLookup() */
2653 XT_PUTPAGE(pmp);
2654
2655 /*
2656 * cmRelocate()
2657 *
2658 * copy target data pages to be relocated;
2659 *
2660 * data extent must start at page boundary and
2661 * multiple of page size (except the last data extent);
2662 * read in each page of the source data extent into cbuf,
2663 * update the cbuf extent descriptor of the page to be
2664 * homeward bound to new dst data extent
2665 * copy the data from the old extent to new extent.
2666 * copy is essential for compressed files to avoid problems
2667 * that can arise if there was a change in compression
2668 * algorithms.
2669 * it is a good strategy because it may disrupt cache
2670 * policy to keep the pages in memory afterwards.
2671 */
2672 offset = xoff << JFS_SBI(ip->i_sb)->l2bsize;
2673 assert((offset & CM_OFFSET) == 0);
2674 nbytes = xlen << JFS_SBI(ip->i_sb)->l2bsize;
2675 pno = offset >> CM_L2BSIZE;
2676 npages = (nbytes + (CM_BSIZE - 1)) >> CM_L2BSIZE;
2677 /*
2678 npages = ((offset + nbytes - 1) >> CM_L2BSIZE) -
2679 (offset >> CM_L2BSIZE) + 1;
2680 */
2681 sxaddr = oxaddr;
2682 dxaddr = nxaddr;
2683
2684 /* process the request one cache buffer at a time */
2685 for (nbrd = 0; nbrd < nbytes; nbrd += nb,
2686 offset += nb, pno++, npages--) {
2687 /* compute page size */
2688 nb = min(nbytes - nbrd, CM_BSIZE);
2689
2690 /* get the cache buffer of the page */
2691 if (rc = cmRead(ip, offset, npages, &cp))
2692 break;
2693
2694 assert(addressPXD(&cp->cm_pxd) == sxaddr);
2695 assert(!cp->cm_modified);
2696
2697 /* bind buffer with the new extent address */
2698 nblks = nb >> JFS_IP(ip->i_sb)->l2bsize;
2699 cmSetXD(ip, cp, pno, dxaddr, nblks);
2700
2701 /* release the cbuf, mark it as modified */
2702 cmPut(cp, true);
2703
2704 dxaddr += nblks;
2705 sxaddr += nblks;
2706 }
2707
2708 /* get back parent page */
2709 if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
2710 return rc;
2711
2712 XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2713 jfs_info("xtRelocate: target data extent relocated.");
2714 } else { /* (xtype == XTPAGE) */
2715
2716 /*
2717 * read in the target xtpage from the source extent;
2718 */
2719 XT_GETPAGE(ip, oxaddr, mp, PSIZE, p, rc);
2720 if (rc) {
2721 XT_PUTPAGE(pmp);
2722 return rc;
2723 }
2724
2725 /*
2726 * read in sibling pages if any to update sibling pointers;
2727 */
2728 rmp = NULL;
2729 if (p->header.next) {
2730 nextbn = le64_to_cpu(p->header.next);
2731 XT_GETPAGE(ip, nextbn, rmp, PSIZE, rp, rc);
2732 if (rc) {
2733 XT_PUTPAGE(pmp);
2734 XT_PUTPAGE(mp);
2735 return (rc);
2736 }
2737 }
2738
2739 lmp = NULL;
2740 if (p->header.prev) {
2741 prevbn = le64_to_cpu(p->header.prev);
2742 XT_GETPAGE(ip, prevbn, lmp, PSIZE, lp, rc);
2743 if (rc) {
2744 XT_PUTPAGE(pmp);
2745 XT_PUTPAGE(mp);
2746 if (rmp)
2747 XT_PUTPAGE(rmp);
2748 return (rc);
2749 }
2750 }
2751
2752 /* at this point, all xtpages to be updated are in memory */
2753
2754 /*
2755 * update sibling pointers of sibling xtpages if any;
2756 */
2757 if (lmp) {
2758 BT_MARK_DIRTY(lmp, ip);
2759 tlck = txLock(tid, ip, lmp, tlckXTREE | tlckRELINK);
2760 lp->header.next = cpu_to_le64(nxaddr);
2761 XT_PUTPAGE(lmp);
2762 }
2763
2764 if (rmp) {
2765 BT_MARK_DIRTY(rmp, ip);
2766 tlck = txLock(tid, ip, rmp, tlckXTREE | tlckRELINK);
2767 rp->header.prev = cpu_to_le64(nxaddr);
2768 XT_PUTPAGE(rmp);
2769 }
2770
2771 /*
2772 * update the target xtpage to be relocated
2773 *
2774 * update the self address of the target page
2775 * and write to destination extent;
2776 * redo image covers the whole xtpage since it is new page
2777 * to the destination extent;
2778 * update of bmap for the free of source extent
2779 * of the target xtpage itself:
2780 * update of bmap for the allocation of destination extent
2781 * of the target xtpage itself:
2782 * update of bmap for the extents covered by xad entries in
2783 * the target xtpage is not necessary since they are not
2784 * updated;
2785 * if not committed before this relocation,
2786 * target page may contain XAD_NEW entries which must
2787 * be scanned for bmap update (logredo() always
2788 * scan xtpage REDOPAGE image for bmap update);
2789 * if committed before this relocation (tlckRELOCATE),
2790 * scan may be skipped by commit() and logredo();
2791 */
2792 BT_MARK_DIRTY(mp, ip);
2793 /* tlckNEW init xtlck->lwm.offset = XTENTRYSTART; */
2794 tlck = txLock(tid, ip, mp, tlckXTREE | tlckNEW);
2795 xtlck = (struct xtlock *) & tlck->lock;
2796
2797 /* update the self address in the xtpage header */
2798 pxd = &p->header.self;
2799 PXDaddress(pxd, nxaddr);
2800
2801 /* linelock for the after image of the whole page */
2802 xtlck->lwm.length =
2803 le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
2804
2805 /* update the buffer extent descriptor of target xtpage */
2806 xsize = xlen << JFS_SBI(ip->i_sb)->l2bsize;
2807 bmSetXD(mp, nxaddr, xsize);
2808
2809 /* unpin the target page to new homeward bound */
2810 XT_PUTPAGE(mp);
2811 jfs_info("xtRelocate: target xtpage relocated.");
2812 }
2813
2814 /*
2815 * 3. acquire maplock for the source extent to be freed;
2816 *
2817 * acquire a maplock saving the src relocated extent address;
2818 * to free of the extent at commit time;
2819 */
2820 out:
2821 /* if DATAEXT relocation, write a LOG_UPDATEMAP record for
2822 * free PXD of the source data extent (logredo() will update
2823 * bmap for free of source data extent), and update bmap for
2824 * free of the source data extent;
2825 */
2826 if (xtype == DATAEXT)
2827 tlck = txMaplock(tid, ip, tlckMAP);
2828 /* if XTPAGE relocation, write a LOG_NOREDOPAGE record
2829 * for the source xtpage (logredo() will init NoRedoPage
2830 * filter and will also update bmap for free of the source
2831 * xtpage), and update bmap for free of the source xtpage;
2832 * N.B. We use tlckMAP instead of tlkcXTREE because there
2833 * is no buffer associated with this lock since the buffer
2834 * has been redirected to the target location.
2835 */
2836 else /* (xtype == XTPAGE) */
2837 tlck = txMaplock(tid, ip, tlckMAP | tlckRELOCATE);
2838
2839 pxdlock = (struct pxd_lock *) & tlck->lock;
2840 pxdlock->flag = mlckFREEPXD;
2841 PXDaddress(&pxdlock->pxd, oxaddr);
2842 PXDlength(&pxdlock->pxd, xlen);
2843 pxdlock->index = 1;
2844
2845 /*
2846 * 4. update the parent xad entry for relocation;
2847 *
2848 * acquire tlck for the parent entry with XAD_NEW as entry
2849 * update which will write LOG_REDOPAGE and update bmap for
2850 * allocation of XAD_NEW destination extent;
2851 */
2852 jfs_info("xtRelocate: update parent xad entry.");
2853 BT_MARK_DIRTY(pmp, ip);
2854 tlck = txLock(tid, ip, pmp, tlckXTREE | tlckGROW);
2855 xtlck = (struct xtlock *) & tlck->lock;
2856
2857 /* update the XAD with the new destination extent; */
2858 xad = &pp->xad[index];
2859 xad->flag |= XAD_NEW;
2860 XADaddress(xad, nxaddr);
2861
2862 xtlck->lwm.offset = min(index, xtlck->lwm.offset);
2863 xtlck->lwm.length = le16_to_cpu(pp->header.nextindex) -
2864 xtlck->lwm.offset;
2865
2866 /* unpin the parent xtpage */
2867 XT_PUTPAGE(pmp);
2868
2869 return rc;
2870 }
2871
2872
2873 /*
2874 * xtSearchNode()
2875 *
2876 * function: search for the internal xad entry covering specified extent.
2877 * This function is mainly used by defragfs utility.
2878 *
2879 * parameters:
2880 * ip - file object;
2881 * xad - extent to find;
2882 * cmpp - comparison result:
2883 * btstack - traverse stack;
2884 * flag - search process flag;
2885 *
2886 * returns:
2887 * btstack contains (bn, index) of search path traversed to the entry.
2888 * *cmpp is set to result of comparison with the entry returned.
2889 * the page containing the entry is pinned at exit.
2890 */
2891 static int xtSearchNode(struct inode *ip, xad_t * xad, /* required XAD entry */
2892 int *cmpp, struct btstack * btstack, int flag)
2893 {
2894 int rc = 0;
2895 s64 xoff, xaddr;
2896 int xlen;
2897 int cmp = 1; /* init for empty page */
2898 s64 bn; /* block number */
2899 struct metapage *mp; /* meta-page buffer */
2900 xtpage_t *p; /* page */
2901 int base, index, lim;
2902 struct btframe *btsp;
2903 s64 t64;
2904
2905 BT_CLR(btstack);
2906
2907 xoff = offsetXAD(xad);
2908 xlen = lengthXAD(xad);
2909 xaddr = addressXAD(xad);
2910
2911 /*
2912 * search down tree from root:
2913 *
2914 * between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
2915 * internal page, child page Pi contains entry with k, Ki <= K < Kj.
2916 *
2917 * if entry with search key K is not found
2918 * internal page search find the entry with largest key Ki
2919 * less than K which point to the child page to search;
2920 * leaf page search find the entry with smallest key Kj
2921 * greater than K so that the returned index is the position of
2922 * the entry to be shifted right for insertion of new entry.
2923 * for empty tree, search key is greater than any key of the tree.
2924 *
2925 * by convention, root bn = 0.
2926 */
2927 for (bn = 0;;) {
2928 /* get/pin the page to search */
2929 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2930 if (rc)
2931 return rc;
2932 if (p->header.flag & BT_LEAF) {
2933 XT_PUTPAGE(mp);
2934 return -ESTALE;
2935 }
2936
2937 lim = le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
2938
2939 /*
2940 * binary search with search key K on the current page
2941 */
2942 for (base = XTENTRYSTART; lim; lim >>= 1) {
2943 index = base + (lim >> 1);
2944
2945 XT_CMP(cmp, xoff, &p->xad[index], t64);
2946 if (cmp == 0) {
2947 /*
2948 * search hit
2949 *
2950 * verify for exact match;
2951 */
2952 if (xaddr == addressXAD(&p->xad[index]) &&
2953 xoff == offsetXAD(&p->xad[index])) {
2954 *cmpp = cmp;
2955
2956 /* save search result */
2957 btsp = btstack->top;
2958 btsp->bn = bn;
2959 btsp->index = index;
2960 btsp->mp = mp;
2961
2962 return 0;
2963 }
2964
2965 /* descend/search its child page */
2966 goto next;
2967 }
2968
2969 if (cmp > 0) {
2970 base = index + 1;
2971 --lim;
2972 }
2973 }
2974
2975 /*
2976 * search miss - non-leaf page:
2977 *
2978 * base is the smallest index with key (Kj) greater than
2979 * search key (K) and may be zero or maxentry index.
2980 * if base is non-zero, decrement base by one to get the parent
2981 * entry of the child page to search.
2982 */
2983 index = base ? base - 1 : base;
2984
2985 /*
2986 * go down to child page
2987 */
2988 next:
2989 /* get the child page block number */
2990 bn = addressXAD(&p->xad[index]);
2991
2992 /* unpin the parent page */
2993 XT_PUTPAGE(mp);
2994 }
2995 }
2996
2997
2998 /*
2999 * xtRelink()
3000 *
3001 * function:
3002 * link around a freed page.
3003 *
3004 * Parameter:
3005 * int tid,
3006 * struct inode *ip,
3007 * xtpage_t *p)
3008 *
3009 * returns:
3010 */
3011 static int xtRelink(tid_t tid, struct inode *ip, xtpage_t * p)
3012 {
3013 int rc = 0;
3014 struct metapage *mp;
3015 s64 nextbn, prevbn;
3016 struct tlock *tlck;
3017
3018 nextbn = le64_to_cpu(p->header.next);
3019 prevbn = le64_to_cpu(p->header.prev);
3020
3021 /* update prev pointer of the next page */
3022 if (nextbn != 0) {
3023 XT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
3024 if (rc)
3025 return rc;
3026
3027 /*
3028 * acquire a transaction lock on the page;
3029 *
3030 * action: update prev pointer;
3031 */
3032 BT_MARK_DIRTY(mp, ip);
3033 tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
3034
3035 /* the page may already have been tlock'd */
3036
3037 p->header.prev = cpu_to_le64(prevbn);
3038
3039 XT_PUTPAGE(mp);
3040 }
3041
3042 /* update next pointer of the previous page */
3043 if (prevbn != 0) {
3044 XT_GETPAGE(ip, prevbn, mp, PSIZE, p, rc);
3045 if (rc)
3046 return rc;
3047
3048 /*
3049 * acquire a transaction lock on the page;
3050 *
3051 * action: update next pointer;
3052 */
3053 BT_MARK_DIRTY(mp, ip);
3054 tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
3055
3056 /* the page may already have been tlock'd */
3057
3058 p->header.next = le64_to_cpu(nextbn);
3059
3060 XT_PUTPAGE(mp);
3061 }
3062
3063 return 0;
3064 }
3065 #endif /* _STILL_TO_PORT */
3066
3067
3068 /*
3069 * xtInitRoot()
3070 *
3071 * initialize file root (inline in inode)
3072 */
3073 void xtInitRoot(tid_t tid, struct inode *ip)
3074 {
3075 xtpage_t *p;
3076
3077 /*
3078 * acquire a transaction lock on the root
3079 *
3080 * action:
3081 */
3082 txLock(tid, ip, (struct metapage *) &JFS_IP(ip)->bxflag,
3083 tlckXTREE | tlckNEW);
3084 p = &JFS_IP(ip)->i_xtroot;
3085
3086 p->header.flag = DXD_INDEX | BT_ROOT | BT_LEAF;
3087 p->header.nextindex = cpu_to_le16(XTENTRYSTART);
3088
3089 if (S_ISDIR(ip->i_mode))
3090 p->header.maxentry = cpu_to_le16(XTROOTINITSLOT_DIR);
3091 else {
3092 p->header.maxentry = cpu_to_le16(XTROOTINITSLOT);
3093 ip->i_size = 0;
3094 }
3095
3096
3097 return;
3098 }
3099
3100
3101 /*
3102 * We can run into a deadlock truncating a file with a large number of
3103 * xtree pages (large fragmented file). A robust fix would entail a
3104 * reservation system where we would reserve a number of metadata pages
3105 * and tlocks which we would be guaranteed without a deadlock. Without
3106 * this, a partial fix is to limit number of metadata pages we will lock
3107 * in a single transaction. Currently we will truncate the file so that
3108 * no more than 50 leaf pages will be locked. The caller of xtTruncate
3109 * will be responsible for ensuring that the current transaction gets
3110 * committed, and that subsequent transactions are created to truncate
3111 * the file further if needed.
3112 */
3113 #define MAX_TRUNCATE_LEAVES 50
3114
3115 /*
3116 * xtTruncate()
3117 *
3118 * function:
3119 * traverse for truncation logging backward bottom up;
3120 * terminate at the last extent entry at the current subtree
3121 * root page covering new down size.
3122 * truncation may occur within the last extent entry.
3123 *
3124 * parameter:
3125 * int tid,
3126 * struct inode *ip,
3127 * s64 newsize,
3128 * int type) {PWMAP, PMAP, WMAP; DELETE, TRUNCATE}
3129 *
3130 * return:
3131 *
3132 * note:
3133 * PWMAP:
3134 * 1. truncate (non-COMMIT_NOLINK file)
3135 * by jfs_truncate() or jfs_open(O_TRUNC):
3136 * xtree is updated;
3137 * 2. truncate index table of directory when last entry removed
3138 * map update via tlock at commit time;
3139 * PMAP:
3140 * Call xtTruncate_pmap instead
3141 * WMAP:
3142 * 1. remove (free zero link count) on last reference release
3143 * (pmap has been freed at commit zero link count);
3144 * 2. truncate (COMMIT_NOLINK file, i.e., tmp file):
3145 * xtree is updated;
3146 * map update directly at truncation time;
3147 *
3148 * if (DELETE)
3149 * no LOG_NOREDOPAGE is required (NOREDOFILE is sufficient);
3150 * else if (TRUNCATE)
3151 * must write LOG_NOREDOPAGE for deleted index page;
3152 *
3153 * pages may already have been tlocked by anonymous transactions
3154 * during file growth (i.e., write) before truncation;
3155 *
3156 * except last truncated entry, deleted entries remains as is
3157 * in the page (nextindex is updated) for other use
3158 * (e.g., log/update allocation map): this avoid copying the page
3159 * info but delay free of pages;
3160 *
3161 */
3162 s64 xtTruncate(tid_t tid, struct inode *ip, s64 newsize, int flag)
3163 {
3164 int rc = 0;
3165 s64 teof;
3166 struct metapage *mp;
3167 xtpage_t *p;
3168 s64 bn;
3169 int index, nextindex;
3170 xad_t *xad;
3171 s64 xoff, xaddr;
3172 int xlen, len, freexlen;
3173 struct btstack btstack;
3174 struct btframe *parent;
3175 struct tblock *tblk = NULL;
3176 struct tlock *tlck = NULL;
3177 struct xtlock *xtlck = NULL;
3178 struct xdlistlock xadlock; /* maplock for COMMIT_WMAP */
3179 struct pxd_lock *pxdlock; /* maplock for COMMIT_WMAP */
3180 s64 nfreed;
3181 int freed, log;
3182 int locked_leaves = 0;
3183
3184 /* save object truncation type */
3185 if (tid) {
3186 tblk = tid_to_tblock(tid);
3187 tblk->xflag |= flag;
3188 }
3189
3190 nfreed = 0;
3191
3192 flag &= COMMIT_MAP;
3193 assert(flag != COMMIT_PMAP);
3194
3195 if (flag == COMMIT_PWMAP)
3196 log = 1;
3197 else {
3198 log = 0;
3199 xadlock.flag = mlckFREEXADLIST;
3200 xadlock.index = 1;
3201 }
3202
3203 /*
3204 * if the newsize is not an integral number of pages,
3205 * the file between newsize and next page boundary will
3206 * be cleared.
3207 * if truncating into a file hole, it will cause
3208 * a full block to be allocated for the logical block.
3209 */
3210
3211 /*
3212 * release page blocks of truncated region <teof, eof>
3213 *
3214 * free the data blocks from the leaf index blocks.
3215 * delete the parent index entries corresponding to
3216 * the freed child data/index blocks.
3217 * free the index blocks themselves which aren't needed
3218 * in new sized file.
3219 *
3220 * index blocks are updated only if the blocks are to be
3221 * retained in the new sized file.
3222 * if type is PMAP, the data and index pages are NOT
3223 * freed, and the data and index blocks are NOT freed
3224 * from working map.
3225 * (this will allow continued access of data/index of
3226 * temporary file (zerolink count file truncated to zero-length)).
3227 */
3228 teof = (newsize + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
3229 JFS_SBI(ip->i_sb)->l2bsize;
3230
3231 /* clear stack */
3232 BT_CLR(&btstack);
3233
3234 /*
3235 * start with root
3236 *
3237 * root resides in the inode
3238 */
3239 bn = 0;
3240
3241 /*
3242 * first access of each page:
3243 */
3244 getPage:
3245 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3246 if (rc)
3247 return rc;
3248
3249 /* process entries backward from last index */
3250 index = le16_to_cpu(p->header.nextindex) - 1;
3251
3252
3253 /* Since this is the rightmost page at this level, and we may have
3254 * already freed a page that was formerly to the right, let's make
3255 * sure that the next pointer is zero.
3256 */
3257 if (p->header.next) {
3258 if (log)
3259 /*
3260 * Make sure this change to the header is logged.
3261 * If we really truncate this leaf, the flag
3262 * will be changed to tlckTRUNCATE
3263 */
3264 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
3265 BT_MARK_DIRTY(mp, ip);
3266 p->header.next = 0;
3267 }
3268
3269 if (p->header.flag & BT_INTERNAL)
3270 goto getChild;
3271
3272 /*
3273 * leaf page
3274 */
3275 freed = 0;
3276
3277 /* does region covered by leaf page precede Teof ? */
3278 xad = &p->xad[index];
3279 xoff = offsetXAD(xad);
3280 xlen = lengthXAD(xad);
3281 if (teof >= xoff + xlen) {
3282 XT_PUTPAGE(mp);
3283 goto getParent;
3284 }
3285
3286 /* (re)acquire tlock of the leaf page */
3287 if (log) {
3288 if (++locked_leaves > MAX_TRUNCATE_LEAVES) {
3289 /*
3290 * We need to limit the size of the transaction
3291 * to avoid exhausting pagecache & tlocks
3292 */
3293 XT_PUTPAGE(mp);
3294 newsize = (xoff + xlen) << JFS_SBI(ip->i_sb)->l2bsize;
3295 goto getParent;
3296 }
3297 tlck = txLock(tid, ip, mp, tlckXTREE);
3298 tlck->type = tlckXTREE | tlckTRUNCATE;
3299 xtlck = (struct xtlock *) & tlck->lock;
3300 xtlck->hwm.offset = le16_to_cpu(p->header.nextindex) - 1;
3301 }
3302 BT_MARK_DIRTY(mp, ip);
3303
3304 /*
3305 * scan backward leaf page entries
3306 */
3307 for (; index >= XTENTRYSTART; index--) {
3308 xad = &p->xad[index];
3309 xoff = offsetXAD(xad);
3310 xlen = lengthXAD(xad);
3311 xaddr = addressXAD(xad);
3312
3313 /*
3314 * The "data" for a directory is indexed by the block
3315 * device's address space. This metadata must be invalidated
3316 * here
3317 */
3318 if (S_ISDIR(ip->i_mode) && (teof == 0))
3319 invalidate_xad_metapages(ip, *xad);
3320 /*
3321 * entry beyond eof: continue scan of current page
3322 * xad
3323 * ---|---=======------->
3324 * eof
3325 */
3326 if (teof < xoff) {
3327 nfreed += xlen;
3328 continue;
3329 }
3330
3331 /*
3332 * (xoff <= teof): last entry to be deleted from page;
3333 * If other entries remain in page: keep and update the page.
3334 */
3335
3336 /*
3337 * eof == entry_start: delete the entry
3338 * xad
3339 * -------|=======------->
3340 * eof
3341 *
3342 */
3343 if (teof == xoff) {
3344 nfreed += xlen;
3345
3346 if (index == XTENTRYSTART)
3347 break;
3348
3349 nextindex = index;
3350 }
3351 /*
3352 * eof within the entry: truncate the entry.
3353 * xad
3354 * -------===|===------->
3355 * eof
3356 */
3357 else if (teof < xoff + xlen) {
3358 /* update truncated entry */
3359 len = teof - xoff;
3360 freexlen = xlen - len;
3361 XADlength(xad, len);
3362
3363 /* save pxd of truncated extent in tlck */
3364 xaddr += len;
3365 if (log) { /* COMMIT_PWMAP */
3366 xtlck->lwm.offset = (xtlck->lwm.offset) ?
3367 min(index, (int)xtlck->lwm.offset) : index;
3368 xtlck->lwm.length = index + 1 -
3369 xtlck->lwm.offset;
3370 xtlck->twm.offset = index;
3371 pxdlock = (struct pxd_lock *) & xtlck->pxdlock;
3372 pxdlock->flag = mlckFREEPXD;
3373 PXDaddress(&pxdlock->pxd, xaddr);
3374 PXDlength(&pxdlock->pxd, freexlen);
3375 }
3376 /* free truncated extent */
3377 else { /* COMMIT_WMAP */
3378
3379 pxdlock = (struct pxd_lock *) & xadlock;
3380 pxdlock->flag = mlckFREEPXD;
3381 PXDaddress(&pxdlock->pxd, xaddr);
3382 PXDlength(&pxdlock->pxd, freexlen);
3383 txFreeMap(ip, pxdlock, NULL, COMMIT_WMAP);
3384
3385 /* reset map lock */
3386 xadlock.flag = mlckFREEXADLIST;
3387 }
3388
3389 /* current entry is new last entry; */
3390 nextindex = index + 1;
3391
3392 nfreed += freexlen;
3393 }
3394 /*
3395 * eof beyond the entry:
3396 * xad
3397 * -------=======---|--->
3398 * eof
3399 */
3400 else { /* (xoff + xlen < teof) */
3401
3402 nextindex = index + 1;
3403 }
3404
3405 if (nextindex < le16_to_cpu(p->header.nextindex)) {
3406 if (!log) { /* COMMIT_WAMP */
3407 xadlock.xdlist = &p->xad[nextindex];
3408 xadlock.count =
3409 le16_to_cpu(p->header.nextindex) -
3410 nextindex;
3411 txFreeMap(ip, (struct maplock *) & xadlock,
3412 NULL, COMMIT_WMAP);
3413 }
3414 p->header.nextindex = cpu_to_le16(nextindex);
3415 }
3416
3417 XT_PUTPAGE(mp);
3418
3419 /* assert(freed == 0); */
3420 goto getParent;
3421 } /* end scan of leaf page entries */
3422
3423 freed = 1;
3424
3425 /*
3426 * leaf page become empty: free the page if type != PMAP
3427 */
3428 if (log) { /* COMMIT_PWMAP */
3429 /* txCommit() with tlckFREE:
3430 * free data extents covered by leaf [XTENTRYSTART:hwm);
3431 * invalidate leaf if COMMIT_PWMAP;
3432 * if (TRUNCATE), will write LOG_NOREDOPAGE;
3433 */
3434 tlck->type = tlckXTREE | tlckFREE;
3435 } else { /* COMMIT_WAMP */
3436
3437 /* free data extents covered by leaf */
3438 xadlock.xdlist = &p->xad[XTENTRYSTART];
3439 xadlock.count =
3440 le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
3441 txFreeMap(ip, (struct maplock *) & xadlock, NULL, COMMIT_WMAP);
3442 }
3443
3444 if (p->header.flag & BT_ROOT) {
3445 p->header.flag &= ~BT_INTERNAL;
3446 p->header.flag |= BT_LEAF;
3447 p->header.nextindex = cpu_to_le16(XTENTRYSTART);
3448
3449 XT_PUTPAGE(mp); /* debug */
3450 goto out;
3451 } else {
3452 if (log) { /* COMMIT_PWMAP */
3453 /* page will be invalidated at tx completion
3454 */
3455 XT_PUTPAGE(mp);
3456 } else { /* COMMIT_WMAP */
3457
3458 if (mp->lid)
3459 lid_to_tlock(mp->lid)->flag |= tlckFREELOCK;
3460
3461 /* invalidate empty leaf page */
3462 discard_metapage(mp);
3463 }
3464 }
3465
3466 /*
3467 * the leaf page become empty: delete the parent entry
3468 * for the leaf page if the parent page is to be kept
3469 * in the new sized file.
3470 */
3471
3472 /*
3473 * go back up to the parent page
3474 */
3475 getParent:
3476 /* pop/restore parent entry for the current child page */
3477 if ((parent = BT_POP(&btstack)) == NULL)
3478 /* current page must have been root */
3479 goto out;
3480
3481 /* get back the parent page */
3482 bn = parent->bn;
3483 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3484 if (rc)
3485 return rc;
3486
3487 index = parent->index;
3488
3489 /*
3490 * child page was not empty:
3491 */
3492 if (freed == 0) {
3493 /* has any entry deleted from parent ? */
3494 if (index < le16_to_cpu(p->header.nextindex) - 1) {
3495 /* (re)acquire tlock on the parent page */
3496 if (log) { /* COMMIT_PWMAP */
3497 /* txCommit() with tlckTRUNCATE:
3498 * free child extents covered by parent [);
3499 */
3500 tlck = txLock(tid, ip, mp, tlckXTREE);
3501 xtlck = (struct xtlock *) & tlck->lock;
3502 if (!(tlck->type & tlckTRUNCATE)) {
3503 xtlck->hwm.offset =
3504 le16_to_cpu(p->header.
3505 nextindex) - 1;
3506 tlck->type =
3507 tlckXTREE | tlckTRUNCATE;
3508 }
3509 } else { /* COMMIT_WMAP */
3510
3511 /* free child extents covered by parent */
3512 xadlock.xdlist = &p->xad[index + 1];
3513 xadlock.count =
3514 le16_to_cpu(p->header.nextindex) -
3515 index - 1;
3516 txFreeMap(ip, (struct maplock *) & xadlock,
3517 NULL, COMMIT_WMAP);
3518 }
3519 BT_MARK_DIRTY(mp, ip);
3520
3521 p->header.nextindex = cpu_to_le16(index + 1);
3522 }
3523 XT_PUTPAGE(mp);
3524 goto getParent;
3525 }
3526
3527 /*
3528 * child page was empty:
3529 */
3530 nfreed += lengthXAD(&p->xad[index]);
3531
3532 /*
3533 * During working map update, child page's tlock must be handled
3534 * before parent's. This is because the parent's tlock will cause
3535 * the child's disk space to be marked available in the wmap, so
3536 * it's important that the child page be released by that time.
3537 *
3538 * ToDo: tlocks should be on doubly-linked list, so we can
3539 * quickly remove it and add it to the end.
3540 */
3541
3542 /*
3543 * Move parent page's tlock to the end of the tid's tlock list
3544 */
3545 if (log && mp->lid && (tblk->last != mp->lid) &&
3546 lid_to_tlock(mp->lid)->tid) {
3547 lid_t lid = mp->lid;
3548 struct tlock *prev;
3549
3550 tlck = lid_to_tlock(lid);
3551
3552 if (tblk->next == lid)
3553 tblk->next = tlck->next;
3554 else {
3555 for (prev = lid_to_tlock(tblk->next);
3556 prev->next != lid;
3557 prev = lid_to_tlock(prev->next)) {
3558 assert(prev->next);
3559 }
3560 prev->next = tlck->next;
3561 }
3562 lid_to_tlock(tblk->last)->next = lid;
3563 tlck->next = 0;
3564 tblk->last = lid;
3565 }
3566
3567 /*
3568 * parent page become empty: free the page
3569 */
3570 if (index == XTENTRYSTART) {
3571 if (log) { /* COMMIT_PWMAP */
3572 /* txCommit() with tlckFREE:
3573 * free child extents covered by parent;
3574 * invalidate parent if COMMIT_PWMAP;
3575 */
3576 tlck = txLock(tid, ip, mp, tlckXTREE);
3577 xtlck = (struct xtlock *) & tlck->lock;
3578 xtlck->hwm.offset =
3579 le16_to_cpu(p->header.nextindex) - 1;
3580 tlck->type = tlckXTREE | tlckFREE;
3581 } else { /* COMMIT_WMAP */
3582
3583 /* free child extents covered by parent */
3584 xadlock.xdlist = &p->xad[XTENTRYSTART];
3585 xadlock.count =
3586 le16_to_cpu(p->header.nextindex) -
3587 XTENTRYSTART;
3588 txFreeMap(ip, (struct maplock *) & xadlock, NULL,
3589 COMMIT_WMAP);
3590 }
3591 BT_MARK_DIRTY(mp, ip);
3592
3593 if (p->header.flag & BT_ROOT) {
3594 p->header.flag &= ~BT_INTERNAL;
3595 p->header.flag |= BT_LEAF;
3596 p->header.nextindex = cpu_to_le16(XTENTRYSTART);
3597 if (le16_to_cpu(p->header.maxentry) == XTROOTMAXSLOT) {
3598 /*
3599 * Shrink root down to allow inline
3600 * EA (otherwise fsck complains)
3601 */
3602 p->header.maxentry =
3603 cpu_to_le16(XTROOTINITSLOT);
3604 JFS_IP(ip)->mode2 |= INLINEEA;
3605 }
3606
3607 XT_PUTPAGE(mp); /* debug */
3608 goto out;
3609 } else {
3610 if (log) { /* COMMIT_PWMAP */
3611 /* page will be invalidated at tx completion
3612 */
3613 XT_PUTPAGE(mp);
3614 } else { /* COMMIT_WMAP */
3615
3616 if (mp->lid)
3617 lid_to_tlock(mp->lid)->flag |=
3618 tlckFREELOCK;
3619
3620 /* invalidate parent page */
3621 discard_metapage(mp);
3622 }
3623
3624 /* parent has become empty and freed:
3625 * go back up to its parent page
3626 */
3627 /* freed = 1; */
3628 goto getParent;
3629 }
3630 }
3631 /*
3632 * parent page still has entries for front region;
3633 */
3634 else {
3635 /* try truncate region covered by preceding entry
3636 * (process backward)
3637 */
3638 index--;
3639
3640 /* go back down to the child page corresponding
3641 * to the entry
3642 */
3643 goto getChild;
3644 }
3645
3646 /*
3647 * internal page: go down to child page of current entry
3648 */
3649 getChild:
3650 /* save current parent entry for the child page */
3651 if (BT_STACK_FULL(&btstack)) {
3652 jfs_error(ip->i_sb, "stack overrun in xtTruncate!");
3653 XT_PUTPAGE(mp);
3654 return -EIO;
3655 }
3656 BT_PUSH(&btstack, bn, index);
3657
3658 /* get child page */
3659 xad = &p->xad[index];
3660 bn = addressXAD(xad);
3661
3662 /*
3663 * first access of each internal entry:
3664 */
3665 /* release parent page */
3666 XT_PUTPAGE(mp);
3667
3668 /* process the child page */
3669 goto getPage;
3670
3671 out:
3672 /*
3673 * update file resource stat
3674 */
3675 /* set size
3676 */
3677 if (S_ISDIR(ip->i_mode) && !newsize)
3678 ip->i_size = 1; /* fsck hates zero-length directories */
3679 else
3680 ip->i_size = newsize;
3681
3682 /* update quota allocation to reflect freed blocks */
3683 vfs_dq_free_block(ip, nfreed);
3684
3685 /*
3686 * free tlock of invalidated pages
3687 */
3688 if (flag == COMMIT_WMAP)
3689 txFreelock(ip);
3690
3691 return newsize;
3692 }
3693
3694
3695 /*
3696 * xtTruncate_pmap()
3697 *
3698 * function:
3699 * Perform truncate to zero length for deleted file, leaving the
3700 * the xtree and working map untouched. This allows the file to
3701 * be accessed via open file handles, while the delete of the file
3702 * is committed to disk.
3703 *
3704 * parameter:
3705 * tid_t tid,
3706 * struct inode *ip,
3707 * s64 committed_size)
3708 *
3709 * return: new committed size
3710 *
3711 * note:
3712 *
3713 * To avoid deadlock by holding too many transaction locks, the
3714 * truncation may be broken up into multiple transactions.
3715 * The committed_size keeps track of part of the file has been
3716 * freed from the pmaps.
3717 */
3718 s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size)
3719 {
3720 s64 bn;
3721 struct btstack btstack;
3722 int cmp;
3723 int index;
3724 int locked_leaves = 0;
3725 struct metapage *mp;
3726 xtpage_t *p;
3727 struct btframe *parent;
3728 int rc;
3729 struct tblock *tblk;
3730 struct tlock *tlck = NULL;
3731 xad_t *xad;
3732 int xlen;
3733 s64 xoff;
3734 struct xtlock *xtlck = NULL;
3735
3736 /* save object truncation type */
3737 tblk = tid_to_tblock(tid);
3738 tblk->xflag |= COMMIT_PMAP;
3739
3740 /* clear stack */
3741 BT_CLR(&btstack);
3742
3743 if (committed_size) {
3744 xoff = (committed_size >> JFS_SBI(ip->i_sb)->l2bsize) - 1;
3745 rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
3746 if (rc)
3747 return rc;
3748
3749 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
3750
3751 if (cmp != 0) {
3752 XT_PUTPAGE(mp);
3753 jfs_error(ip->i_sb,
3754 "xtTruncate_pmap: did not find extent");
3755 return -EIO;
3756 }
3757 } else {
3758 /*
3759 * start with root
3760 *
3761 * root resides in the inode
3762 */
3763 bn = 0;
3764
3765 /*
3766 * first access of each page:
3767 */
3768 getPage:
3769 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3770 if (rc)
3771 return rc;
3772
3773 /* process entries backward from last index */
3774 index = le16_to_cpu(p->header.nextindex) - 1;
3775
3776 if (p->header.flag & BT_INTERNAL)
3777 goto getChild;
3778 }
3779
3780 /*
3781 * leaf page
3782 */
3783
3784 if (++locked_leaves > MAX_TRUNCATE_LEAVES) {
3785 /*
3786 * We need to limit the size of the transaction
3787 * to avoid exhausting pagecache & tlocks
3788 */
3789 xad = &p->xad[index];
3790 xoff = offsetXAD(xad);
3791 xlen = lengthXAD(xad);
3792 XT_PUTPAGE(mp);
3793 return (xoff + xlen) << JFS_SBI(ip->i_sb)->l2bsize;
3794 }
3795 tlck = txLock(tid, ip, mp, tlckXTREE);
3796 tlck->type = tlckXTREE | tlckFREE;
3797 xtlck = (struct xtlock *) & tlck->lock;
3798 xtlck->hwm.offset = index;
3799
3800
3801 XT_PUTPAGE(mp);
3802
3803 /*
3804 * go back up to the parent page
3805 */
3806 getParent:
3807 /* pop/restore parent entry for the current child page */
3808 if ((parent = BT_POP(&btstack)) == NULL)
3809 /* current page must have been root */
3810 goto out;
3811
3812 /* get back the parent page */
3813 bn = parent->bn;
3814 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3815 if (rc)
3816 return rc;
3817
3818 index = parent->index;
3819
3820 /*
3821 * parent page become empty: free the page
3822 */
3823 if (index == XTENTRYSTART) {
3824 /* txCommit() with tlckFREE:
3825 * free child extents covered by parent;
3826 * invalidate parent if COMMIT_PWMAP;
3827 */
3828 tlck = txLock(tid, ip, mp, tlckXTREE);
3829 xtlck = (struct xtlock *) & tlck->lock;
3830 xtlck->hwm.offset = le16_to_cpu(p->header.nextindex) - 1;
3831 tlck->type = tlckXTREE | tlckFREE;
3832
3833 XT_PUTPAGE(mp);
3834
3835 if (p->header.flag & BT_ROOT) {
3836
3837 goto out;
3838 } else {
3839 goto getParent;
3840 }
3841 }
3842 /*
3843 * parent page still has entries for front region;
3844 */
3845 else
3846 index--;
3847 /*
3848 * internal page: go down to child page of current entry
3849 */
3850 getChild:
3851 /* save current parent entry for the child page */
3852 if (BT_STACK_FULL(&btstack)) {
3853 jfs_error(ip->i_sb, "stack overrun in xtTruncate_pmap!");
3854 XT_PUTPAGE(mp);
3855 return -EIO;
3856 }
3857 BT_PUSH(&btstack, bn, index);
3858
3859 /* get child page */
3860 xad = &p->xad[index];
3861 bn = addressXAD(xad);
3862
3863 /*
3864 * first access of each internal entry:
3865 */
3866 /* release parent page */
3867 XT_PUTPAGE(mp);
3868
3869 /* process the child page */
3870 goto getPage;
3871
3872 out:
3873
3874 return 0;
3875 }
3876
3877 #ifdef CONFIG_JFS_STATISTICS
3878 static int jfs_xtstat_proc_show(struct seq_file *m, void *v)
3879 {
3880 seq_printf(m,
3881 "JFS Xtree statistics\n"
3882 "====================\n"
3883 "searches = %d\n"
3884 "fast searches = %d\n"
3885 "splits = %d\n",
3886 xtStat.search,
3887 xtStat.fastSearch,
3888 xtStat.split);
3889 return 0;
3890 }
3891
3892 static int jfs_xtstat_proc_open(struct inode *inode, struct file *file)
3893 {
3894 return single_open(file, jfs_xtstat_proc_show, NULL);
3895 }
3896
3897 const struct file_operations jfs_xtstat_proc_fops = {
3898 .owner = THIS_MODULE,
3899 .open = jfs_xtstat_proc_open,
3900 .read = seq_read,
3901 .llseek = seq_lseek,
3902 .release = single_release,
3903 };
3904 #endif
mm of the moment repository