1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) International Business Machines Corp., 2000-2005
4 */
5 /*
6 * jfs_xtree.c: extent allocation descriptor B+-tree manager
7 */
8
9 #include <linux/fs.h>
10 #include <linux/module.h>
11 #include <linux/quotaops.h>
12 #include <linux/seq_file.h>
13 #include "jfs_incore.h"
14 #include "jfs_filsys.h"
15 #include "jfs_metapage.h"
16 #include "jfs_dmap.h"
17 #include "jfs_dinode.h"
18 #include "jfs_superblock.h"
19 #include "jfs_debug.h"
20
21 /*
22 * xtree local flag
23 */
24 #define XT_INSERT 0x00000001
25
26 /*
27 * xtree key/entry comparison: extent offset
28 *
29 * return:
30 * -1: k < start of extent
31 * 0: start_of_extent <= k <= end_of_extent
32 * 1: k > end_of_extent
33 */
34 #define XT_CMP(CMP, K, X, OFFSET64)\
35 {\
36 OFFSET64 = offsetXAD(X);\
37 (CMP) = ((K) >= OFFSET64 + lengthXAD(X)) ? 1 :\
38 ((K) < OFFSET64) ? -1 : 0;\
39 }
40
41 /* write a xad entry */
42 #define XT_PUTENTRY(XAD, FLAG, OFF, LEN, ADDR)\
43 {\
44 (XAD)->flag = (FLAG);\
45 XADoffset((XAD), (OFF));\
46 XADlength((XAD), (LEN));\
47 XADaddress((XAD), (ADDR));\
48 }
49
50 #define XT_PAGE(IP, MP) BT_PAGE(IP, MP, xtpage_t, i_xtroot)
51
52 /* get page buffer for specified block address */
53 /* ToDo: Replace this ugly macro with a function */
54 #define XT_GETPAGE(IP, BN, MP, SIZE, P, RC) \
55 do { \
56 BT_GETPAGE(IP, BN, MP, xtpage_t, SIZE, P, RC, i_xtroot); \
57 if (!(RC)) { \
58 if ((le16_to_cpu((P)->header.nextindex) < XTENTRYSTART) || \
59 (le16_to_cpu((P)->header.nextindex) > \
60 le16_to_cpu((P)->header.maxentry)) || \
61 (le16_to_cpu((P)->header.maxentry) > \
62 (((BN) == 0) ? XTROOTMAXSLOT : PSIZE >> L2XTSLOTSIZE))) { \
63 jfs_error((IP)->i_sb, \
64 "XT_GETPAGE: xtree page corrupt\n"); \
65 BT_PUTPAGE(MP); \
66 MP = NULL; \
67 RC = -EIO; \
68 } \
69 } \
70 } while (0)
71
72 /* for consistency */
73 #define XT_PUTPAGE(MP) BT_PUTPAGE(MP)
74
75 #define XT_GETSEARCH(IP, LEAF, BN, MP, P, INDEX) \
76 BT_GETSEARCH(IP, LEAF, BN, MP, xtpage_t, P, INDEX, i_xtroot)
77 /* xtree entry parameter descriptor */
78 struct xtsplit {
79 struct metapage *mp;
80 s16 index;
81 u8 flag;
82 s64 off;
83 s64 addr;
84 int len;
85 struct pxdlist *pxdlist;
86 };
87
88
89 /*
90 * statistics
91 */
92 #ifdef CONFIG_JFS_STATISTICS
93 static struct {
94 uint search;
95 uint fastSearch;
96 uint split;
97 } xtStat;
98 #endif
99
100
101 /*
102 * forward references
103 */
104 static int xtSearch(struct inode *ip, s64 xoff, s64 *next, int *cmpp,
105 struct btstack * btstack, int flag);
106
107 static int xtSplitUp(tid_t tid,
108 struct inode *ip,
109 struct xtsplit * split, struct btstack * btstack);
110
111 static int xtSplitPage(tid_t tid, struct inode *ip, struct xtsplit * split,
112 struct metapage ** rmpp, s64 * rbnp);
113
114 static int xtSplitRoot(tid_t tid, struct inode *ip,
115 struct xtsplit * split, struct metapage ** rmpp);
116
117 #ifdef _STILL_TO_PORT
118 static int xtDeleteUp(tid_t tid, struct inode *ip, struct metapage * fmp,
119 xtpage_t * fp, struct btstack * btstack);
120
121 static int xtSearchNode(struct inode *ip,
122 xad_t * xad,
123 int *cmpp, struct btstack * btstack, int flag);
124
125 static int xtRelink(tid_t tid, struct inode *ip, xtpage_t * fp);
126 #endif /* _STILL_TO_PORT */
127
128 /*
129 * xtLookup()
130 *
131 * function: map a single page into a physical extent;
132 */
133 int xtLookup(struct inode *ip, s64 lstart,
134 s64 llen, int *pflag, s64 * paddr, s32 * plen, int no_check)
135 {
136 int rc = 0;
137 struct btstack btstack;
138 int cmp;
139 s64 bn;
140 struct metapage *mp;
141 xtpage_t *p;
142 int index;
143 xad_t *xad;
144 s64 next, size, xoff, xend;
145 int xlen;
146 s64 xaddr;
147
148 *paddr = 0;
149 *plen = llen;
150
151 if (!no_check) {
152 /* is lookup offset beyond eof ? */
153 size = ((u64) ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
154 JFS_SBI(ip->i_sb)->l2bsize;
155 if (lstart >= size)
156 return 0;
157 }
158
159 /*
160 * search for the xad entry covering the logical extent
161 */
162 //search:
163 if ((rc = xtSearch(ip, lstart, &next, &cmp, &btstack, 0))) {
164 jfs_err("xtLookup: xtSearch returned %d", rc);
165 return rc;
166 }
167
168 /*
169 * compute the physical extent covering logical extent
170 *
171 * N.B. search may have failed (e.g., hole in sparse file),
172 * and returned the index of the next entry.
173 */
174 /* retrieve search result */
175 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
176
177 /* is xad found covering start of logical extent ?
178 * lstart is a page start address,
179 * i.e., lstart cannot start in a hole;
180 */
181 if (cmp) {
182 if (next)
183 *plen = min(next - lstart, llen);
184 goto out;
185 }
186
187 /*
188 * lxd covered by xad
189 */
190 xad = &p->xad[index];
191 xoff = offsetXAD(xad);
192 xlen = lengthXAD(xad);
193 xend = xoff + xlen;
194 xaddr = addressXAD(xad);
195
196 /* initialize new pxd */
197 *pflag = xad->flag;
198 *paddr = xaddr + (lstart - xoff);
199 /* a page must be fully covered by an xad */
200 *plen = min(xend - lstart, llen);
201
202 out:
203 XT_PUTPAGE(mp);
204
205 return rc;
206 }
207
208 /*
209 * xtSearch()
210 *
211 * function: search for the xad entry covering specified offset.
212 *
213 * parameters:
214 * ip - file object;
215 * xoff - extent offset;
216 * nextp - address of next extent (if any) for search miss
217 * cmpp - comparison result:
218 * btstack - traverse stack;
219 * flag - search process flag (XT_INSERT);
220 *
221 * returns:
222 * btstack contains (bn, index) of search path traversed to the entry.
223 * *cmpp is set to result of comparison with the entry returned.
224 * the page containing the entry is pinned at exit.
225 */
226 static int xtSearch(struct inode *ip, s64 xoff, s64 *nextp,
227 int *cmpp, struct btstack * btstack, int flag)
228 {
229 struct jfs_inode_info *jfs_ip = JFS_IP(ip);
230 int rc = 0;
231 int cmp = 1; /* init for empty page */
232 s64 bn; /* block number */
233 struct metapage *mp; /* page buffer */
234 xtpage_t *p; /* page */
235 xad_t *xad;
236 int base, index, lim, btindex;
237 struct btframe *btsp;
238 int nsplit = 0; /* number of pages to split */
239 s64 t64;
240 s64 next = 0;
241
242 INCREMENT(xtStat.search);
243
244 BT_CLR(btstack);
245
246 btstack->nsplit = 0;
247
248 /*
249 * search down tree from root:
250 *
251 * between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
252 * internal page, child page Pi contains entry with k, Ki <= K < Kj.
253 *
254 * if entry with search key K is not found
255 * internal page search find the entry with largest key Ki
256 * less than K which point to the child page to search;
257 * leaf page search find the entry with smallest key Kj
258 * greater than K so that the returned index is the position of
259 * the entry to be shifted right for insertion of new entry.
260 * for empty tree, search key is greater than any key of the tree.
261 *
262 * by convention, root bn = 0.
263 */
264 for (bn = 0;;) {
265 /* get/pin the page to search */
266 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
267 if (rc)
268 return rc;
269
270 /* try sequential access heuristics with the previous
271 * access entry in target leaf page:
272 * once search narrowed down into the target leaf,
273 * key must either match an entry in the leaf or
274 * key entry does not exist in the tree;
275 */
276 //fastSearch:
277 if ((jfs_ip->btorder & BT_SEQUENTIAL) &&
278 (p->header.flag & BT_LEAF) &&
279 (index = jfs_ip->btindex) <
280 le16_to_cpu(p->header.nextindex)) {
281 xad = &p->xad[index];
282 t64 = offsetXAD(xad);
283 if (xoff < t64 + lengthXAD(xad)) {
284 if (xoff >= t64) {
285 *cmpp = 0;
286 goto out;
287 }
288
289 /* stop sequential access heuristics */
290 goto binarySearch;
291 } else { /* (t64 + lengthXAD(xad)) <= xoff */
292
293 /* try next sequential entry */
294 index++;
295 if (index <
296 le16_to_cpu(p->header.nextindex)) {
297 xad++;
298 t64 = offsetXAD(xad);
299 if (xoff < t64 + lengthXAD(xad)) {
300 if (xoff >= t64) {
301 *cmpp = 0;
302 goto out;
303 }
304
305 /* miss: key falls between
306 * previous and this entry
307 */
308 *cmpp = 1;
309 next = t64;
310 goto out;
311 }
312
313 /* (xoff >= t64 + lengthXAD(xad));
314 * matching entry may be further out:
315 * stop heuristic search
316 */
317 /* stop sequential access heuristics */
318 goto binarySearch;
319 }
320
321 /* (index == p->header.nextindex);
322 * miss: key entry does not exist in
323 * the target leaf/tree
324 */
325 *cmpp = 1;
326 goto out;
327 }
328
329 /*
330 * if hit, return index of the entry found, and
331 * if miss, where new entry with search key is
332 * to be inserted;
333 */
334 out:
335 /* compute number of pages to split */
336 if (flag & XT_INSERT) {
337 if (p->header.nextindex == /* little-endian */
338 p->header.maxentry)
339 nsplit++;
340 else
341 nsplit = 0;
342 btstack->nsplit = nsplit;
343 }
344
345 /* save search result */
346 btsp = btstack->top;
347 btsp->bn = bn;
348 btsp->index = index;
349 btsp->mp = mp;
350
351 /* update sequential access heuristics */
352 jfs_ip->btindex = index;
353
354 if (nextp)
355 *nextp = next;
356
357 INCREMENT(xtStat.fastSearch);
358 return 0;
359 }
360
361 /* well, ... full search now */
362 binarySearch:
363 lim = le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
364
365 /*
366 * binary search with search key K on the current page
367 */
368 for (base = XTENTRYSTART; lim; lim >>= 1) {
369 index = base + (lim >> 1);
370
371 XT_CMP(cmp, xoff, &p->xad[index], t64);
372 if (cmp == 0) {
373 /*
374 * search hit
375 */
376 /* search hit - leaf page:
377 * return the entry found
378 */
379 if (p->header.flag & BT_LEAF) {
380 *cmpp = cmp;
381
382 /* compute number of pages to split */
383 if (flag & XT_INSERT) {
384 if (p->header.nextindex ==
385 p->header.maxentry)
386 nsplit++;
387 else
388 nsplit = 0;
389 btstack->nsplit = nsplit;
390 }
391
392 /* save search result */
393 btsp = btstack->top;
394 btsp->bn = bn;
395 btsp->index = index;
396 btsp->mp = mp;
397
398 /* init sequential access heuristics */
399 btindex = jfs_ip->btindex;
400 if (index == btindex ||
401 index == btindex + 1)
402 jfs_ip->btorder = BT_SEQUENTIAL;
403 else
404 jfs_ip->btorder = BT_RANDOM;
405 jfs_ip->btindex = index;
406
407 return 0;
408 }
409 /* search hit - internal page:
410 * descend/search its child page
411 */
412 if (index < le16_to_cpu(p->header.nextindex)-1)
413 next = offsetXAD(&p->xad[index + 1]);
414 goto next;
415 }
416
417 if (cmp > 0) {
418 base = index + 1;
419 --lim;
420 }
421 }
422
423 /*
424 * search miss
425 *
426 * base is the smallest index with key (Kj) greater than
427 * search key (K) and may be zero or maxentry index.
428 */
429 if (base < le16_to_cpu(p->header.nextindex))
430 next = offsetXAD(&p->xad[base]);
431 /*
432 * search miss - leaf page:
433 *
434 * return location of entry (base) where new entry with
435 * search key K is to be inserted.
436 */
437 if (p->header.flag & BT_LEAF) {
438 *cmpp = cmp;
439
440 /* compute number of pages to split */
441 if (flag & XT_INSERT) {
442 if (p->header.nextindex ==
443 p->header.maxentry)
444 nsplit++;
445 else
446 nsplit = 0;
447 btstack->nsplit = nsplit;
448 }
449
450 /* save search result */
451 btsp = btstack->top;
452 btsp->bn = bn;
453 btsp->index = base;
454 btsp->mp = mp;
455
456 /* init sequential access heuristics */
457 btindex = jfs_ip->btindex;
458 if (base == btindex || base == btindex + 1)
459 jfs_ip->btorder = BT_SEQUENTIAL;
460 else
461 jfs_ip->btorder = BT_RANDOM;
462 jfs_ip->btindex = base;
463
464 if (nextp)
465 *nextp = next;
466
467 return 0;
468 }
469
470 /*
471 * search miss - non-leaf page:
472 *
473 * if base is non-zero, decrement base by one to get the parent
474 * entry of the child page to search.
475 */
476 index = base ? base - 1 : base;
477
478 /*
479 * go down to child page
480 */
481 next:
482 /* update number of pages to split */
483 if (p->header.nextindex == p->header.maxentry)
484 nsplit++;
485 else
486 nsplit = 0;
487
488 /* push (bn, index) of the parent page/entry */
489 if (BT_STACK_FULL(btstack)) {
490 jfs_error(ip->i_sb, "stack overrun!\n");
491 XT_PUTPAGE(mp);
492 return -EIO;
493 }
494 BT_PUSH(btstack, bn, index);
495
496 /* get the child page block number */
497 bn = addressXAD(&p->xad[index]);
498
499 /* unpin the parent page */
500 XT_PUTPAGE(mp);
501 }
502 }
503
504 /*
505 * xtInsert()
506 *
507 * function:
508 *
509 * parameter:
510 * tid - transaction id;
511 * ip - file object;
512 * xflag - extent flag (XAD_NOTRECORDED):
513 * xoff - extent offset;
514 * xlen - extent length;
515 * xaddrp - extent address pointer (in/out):
516 * if (*xaddrp)
517 * caller allocated data extent at *xaddrp;
518 * else
519 * allocate data extent and return its xaddr;
520 * flag -
521 *
522 * return:
523 */
524 int xtInsert(tid_t tid, /* transaction id */
525 struct inode *ip, int xflag, s64 xoff, s32 xlen, s64 * xaddrp,
526 int flag)
527 {
528 int rc = 0;
529 s64 xaddr, hint;
530 struct metapage *mp; /* meta-page buffer */
531 xtpage_t *p; /* base B+-tree index page */
532 s64 bn;
533 int index, nextindex;
534 struct btstack btstack; /* traverse stack */
535 struct xtsplit split; /* split information */
536 xad_t *xad;
537 int cmp;
538 s64 next;
539 struct tlock *tlck;
540 struct xtlock *xtlck;
541
542 jfs_info("xtInsert: nxoff:0x%lx nxlen:0x%x", (ulong) xoff, xlen);
543
544 /*
545 * search for the entry location at which to insert:
546 *
547 * xtFastSearch() and xtSearch() both returns (leaf page
548 * pinned, index at which to insert).
549 * n.b. xtSearch() may return index of maxentry of
550 * the full page.
551 */
552 if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
553 return rc;
554
555 /* retrieve search result */
556 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
557
558 /* This test must follow XT_GETSEARCH since mp must be valid if
559 * we branch to out: */
560 if ((cmp == 0) || (next && (xlen > next - xoff))) {
561 rc = -EEXIST;
562 goto out;
563 }
564
565 /*
566 * allocate data extent requested
567 *
568 * allocation hint: last xad
569 */
570 if ((xaddr = *xaddrp) == 0) {
571 if (index > XTENTRYSTART) {
572 xad = &p->xad[index - 1];
573 hint = addressXAD(xad) + lengthXAD(xad) - 1;
574 } else
575 hint = 0;
576 if ((rc = dquot_alloc_block(ip, xlen)))
577 goto out;
578 if ((rc = dbAlloc(ip, hint, (s64) xlen, &xaddr))) {
579 dquot_free_block(ip, xlen);
580 goto out;
581 }
582 }
583
584 /*
585 * insert entry for new extent
586 */
587 xflag |= XAD_NEW;
588
589 /*
590 * if the leaf page is full, split the page and
591 * propagate up the router entry for the new page from split
592 *
593 * The xtSplitUp() will insert the entry and unpin the leaf page.
594 */
595 nextindex = le16_to_cpu(p->header.nextindex);
596 if (nextindex == le16_to_cpu(p->header.maxentry)) {
597 split.mp = mp;
598 split.index = index;
599 split.flag = xflag;
600 split.off = xoff;
601 split.len = xlen;
602 split.addr = xaddr;
603 split.pxdlist = NULL;
604 if ((rc = xtSplitUp(tid, ip, &split, &btstack))) {
605 /* undo data extent allocation */
606 if (*xaddrp == 0) {
607 dbFree(ip, xaddr, (s64) xlen);
608 dquot_free_block(ip, xlen);
609 }
610 return rc;
611 }
612
613 *xaddrp = xaddr;
614 return 0;
615 }
616
617 /*
618 * insert the new entry into the leaf page
619 */
620 /*
621 * acquire a transaction lock on the leaf page;
622 *
623 * action: xad insertion/extension;
624 */
625 BT_MARK_DIRTY(mp, ip);
626
627 /* if insert into middle, shift right remaining entries. */
628 if (index < nextindex)
629 memmove(&p->xad[index + 1], &p->xad[index],
630 (nextindex - index) * sizeof(xad_t));
631
632 /* insert the new entry: mark the entry NEW */
633 xad = &p->xad[index];
634 XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
635
636 /* advance next available entry index */
637 le16_add_cpu(&p->header.nextindex, 1);
638
639 /* Don't log it if there are no links to the file */
640 if (!test_cflag(COMMIT_Nolink, ip)) {
641 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
642 xtlck = (struct xtlock *) & tlck->lock;
643 xtlck->lwm.offset =
644 (xtlck->lwm.offset) ? min(index,
645 (int)xtlck->lwm.offset) : index;
646 xtlck->lwm.length =
647 le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
648 }
649
650 *xaddrp = xaddr;
651
652 out:
653 /* unpin the leaf page */
654 XT_PUTPAGE(mp);
655
656 return rc;
657 }
658
659
660 /*
661 * xtSplitUp()
662 *
663 * function:
664 * split full pages as propagating insertion up the tree
665 *
666 * parameter:
667 * tid - transaction id;
668 * ip - file object;
669 * split - entry parameter descriptor;
670 * btstack - traverse stack from xtSearch()
671 *
672 * return:
673 */
674 static int
675 xtSplitUp(tid_t tid,
676 struct inode *ip, struct xtsplit * split, struct btstack * btstack)
677 {
678 int rc = 0;
679 struct metapage *smp;
680 xtpage_t *sp; /* split page */
681 struct metapage *rmp;
682 s64 rbn; /* new right page block number */
683 struct metapage *rcmp;
684 xtpage_t *rcp; /* right child page */
685 s64 rcbn; /* right child page block number */
686 int skip; /* index of entry of insertion */
687 int nextindex; /* next available entry index of p */
688 struct btframe *parent; /* parent page entry on traverse stack */
689 xad_t *xad;
690 s64 xaddr;
691 int xlen;
692 int nsplit; /* number of pages split */
693 struct pxdlist pxdlist;
694 pxd_t *pxd;
695 struct tlock *tlck;
696 struct xtlock *xtlck;
697
698 smp = split->mp;
699 sp = XT_PAGE(ip, smp);
700
701 /* is inode xtree root extension/inline EA area free ? */
702 if ((sp->header.flag & BT_ROOT) && (!S_ISDIR(ip->i_mode)) &&
703 (le16_to_cpu(sp->header.maxentry) < XTROOTMAXSLOT) &&
704 (JFS_IP(ip)->mode2 & INLINEEA)) {
705 sp->header.maxentry = cpu_to_le16(XTROOTMAXSLOT);
706 JFS_IP(ip)->mode2 &= ~INLINEEA;
707
708 BT_MARK_DIRTY(smp, ip);
709 /*
710 * acquire a transaction lock on the leaf page;
711 *
712 * action: xad insertion/extension;
713 */
714
715 /* if insert into middle, shift right remaining entries. */
716 skip = split->index;
717 nextindex = le16_to_cpu(sp->header.nextindex);
718 if (skip < nextindex)
719 memmove(&sp->xad[skip + 1], &sp->xad[skip],
720 (nextindex - skip) * sizeof(xad_t));
721
722 /* insert the new entry: mark the entry NEW */
723 xad = &sp->xad[skip];
724 XT_PUTENTRY(xad, split->flag, split->off, split->len,
725 split->addr);
726
727 /* advance next available entry index */
728 le16_add_cpu(&sp->header.nextindex, 1);
729
730 /* Don't log it if there are no links to the file */
731 if (!test_cflag(COMMIT_Nolink, ip)) {
732 tlck = txLock(tid, ip, smp, tlckXTREE | tlckGROW);
733 xtlck = (struct xtlock *) & tlck->lock;
734 xtlck->lwm.offset = (xtlck->lwm.offset) ?
735 min(skip, (int)xtlck->lwm.offset) : skip;
736 xtlck->lwm.length =
737 le16_to_cpu(sp->header.nextindex) -
738 xtlck->lwm.offset;
739 }
740
741 return 0;
742 }
743
744 /*
745 * allocate new index blocks to cover index page split(s)
746 *
747 * allocation hint: ?
748 */
749 if (split->pxdlist == NULL) {
750 nsplit = btstack->nsplit;
751 split->pxdlist = &pxdlist;
752 pxdlist.maxnpxd = pxdlist.npxd = 0;
753 pxd = &pxdlist.pxd[0];
754 xlen = JFS_SBI(ip->i_sb)->nbperpage;
755 for (; nsplit > 0; nsplit--, pxd++) {
756 if ((rc = dbAlloc(ip, (s64) 0, (s64) xlen, &xaddr))
757 == 0) {
758 PXDaddress(pxd, xaddr);
759 PXDlength(pxd, xlen);
760
761 pxdlist.maxnpxd++;
762
763 continue;
764 }
765
766 /* undo allocation */
767
768 XT_PUTPAGE(smp);
769 return rc;
770 }
771 }
772
773 /*
774 * Split leaf page <sp> into <sp> and a new right page <rp>.
775 *
776 * The split routines insert the new entry into the leaf page,
777 * and acquire txLock as appropriate.
778 * return <rp> pinned and its block number <rpbn>.
779 */
780 rc = (sp->header.flag & BT_ROOT) ?
781 xtSplitRoot(tid, ip, split, &rmp) :
782 xtSplitPage(tid, ip, split, &rmp, &rbn);
783
784 XT_PUTPAGE(smp);
785
786 if (rc)
787 return -EIO;
788 /*
789 * propagate up the router entry for the leaf page just split
790 *
791 * insert a router entry for the new page into the parent page,
792 * propagate the insert/split up the tree by walking back the stack
793 * of (bn of parent page, index of child page entry in parent page)
794 * that were traversed during the search for the page that split.
795 *
796 * the propagation of insert/split up the tree stops if the root
797 * splits or the page inserted into doesn't have to split to hold
798 * the new entry.
799 *
800 * the parent entry for the split page remains the same, and
801 * a new entry is inserted at its right with the first key and
802 * block number of the new right page.
803 *
804 * There are a maximum of 3 pages pinned at any time:
805 * right child, left parent and right parent (when the parent splits)
806 * to keep the child page pinned while working on the parent.
807 * make sure that all pins are released at exit.
808 */
809 while ((parent = BT_POP(btstack)) != NULL) {
810 /* parent page specified by stack frame <parent> */
811
812 /* keep current child pages <rcp> pinned */
813 rcmp = rmp;
814 rcbn = rbn;
815 rcp = XT_PAGE(ip, rcmp);
816
817 /*
818 * insert router entry in parent for new right child page <rp>
819 */
820 /* get/pin the parent page <sp> */
821 XT_GETPAGE(ip, parent->bn, smp, PSIZE, sp, rc);
822 if (rc) {
823 XT_PUTPAGE(rcmp);
824 return rc;
825 }
826
827 /*
828 * The new key entry goes ONE AFTER the index of parent entry,
829 * because the split was to the right.
830 */
831 skip = parent->index + 1;
832
833 /*
834 * split or shift right remaining entries of the parent page
835 */
836 nextindex = le16_to_cpu(sp->header.nextindex);
837 /*
838 * parent page is full - split the parent page
839 */
840 if (nextindex == le16_to_cpu(sp->header.maxentry)) {
841 /* init for parent page split */
842 split->mp = smp;
843 split->index = skip; /* index at insert */
844 split->flag = XAD_NEW;
845 split->off = offsetXAD(&rcp->xad[XTENTRYSTART]);
846 split->len = JFS_SBI(ip->i_sb)->nbperpage;
847 split->addr = rcbn;
848
849 /* unpin previous right child page */
850 XT_PUTPAGE(rcmp);
851
852 /* The split routines insert the new entry,
853 * and acquire txLock as appropriate.
854 * return <rp> pinned and its block number <rpbn>.
855 */
856 rc = (sp->header.flag & BT_ROOT) ?
857 xtSplitRoot(tid, ip, split, &rmp) :
858 xtSplitPage(tid, ip, split, &rmp, &rbn);
859 if (rc) {
860 XT_PUTPAGE(smp);
861 return rc;
862 }
863
864 XT_PUTPAGE(smp);
865 /* keep new child page <rp> pinned */
866 }
867 /*
868 * parent page is not full - insert in parent page
869 */
870 else {
871 /*
872 * insert router entry in parent for the right child
873 * page from the first entry of the right child page:
874 */
875 /*
876 * acquire a transaction lock on the parent page;
877 *
878 * action: router xad insertion;
879 */
880 BT_MARK_DIRTY(smp, ip);
881
882 /*
883 * if insert into middle, shift right remaining entries
884 */
885 if (skip < nextindex)
886 memmove(&sp->xad[skip + 1], &sp->xad[skip],
887 (nextindex -
888 skip) << L2XTSLOTSIZE);
889
890 /* insert the router entry */
891 xad = &sp->xad[skip];
892 XT_PUTENTRY(xad, XAD_NEW,
893 offsetXAD(&rcp->xad[XTENTRYSTART]),
894 JFS_SBI(ip->i_sb)->nbperpage, rcbn);
895
896 /* advance next available entry index. */
897 le16_add_cpu(&sp->header.nextindex, 1);
898
899 /* Don't log it if there are no links to the file */
900 if (!test_cflag(COMMIT_Nolink, ip)) {
901 tlck = txLock(tid, ip, smp,
902 tlckXTREE | tlckGROW);
903 xtlck = (struct xtlock *) & tlck->lock;
904 xtlck->lwm.offset = (xtlck->lwm.offset) ?
905 min(skip, (int)xtlck->lwm.offset) : skip;
906 xtlck->lwm.length =
907 le16_to_cpu(sp->header.nextindex) -
908 xtlck->lwm.offset;
909 }
910
911 /* unpin parent page */
912 XT_PUTPAGE(smp);
913
914 /* exit propagate up */
915 break;
916 }
917 }
918
919 /* unpin current right page */
920 XT_PUTPAGE(rmp);
921
922 return 0;
923 }
924
925
926 /*
927 * xtSplitPage()
928 *
929 * function:
930 * split a full non-root page into
931 * original/split/left page and new right page
932 * i.e., the original/split page remains as left page.
933 *
934 * parameter:
935 * int tid,
936 * struct inode *ip,
937 * struct xtsplit *split,
938 * struct metapage **rmpp,
939 * u64 *rbnp,
940 *
941 * return:
942 * Pointer to page in which to insert or NULL on error.
943 */
944 static int
945 xtSplitPage(tid_t tid, struct inode *ip,
946 struct xtsplit * split, struct metapage ** rmpp, s64 * rbnp)
947 {
948 int rc = 0;
949 struct metapage *smp;
950 xtpage_t *sp;
951 struct metapage *rmp;
952 xtpage_t *rp; /* new right page allocated */
953 s64 rbn; /* new right page block number */
954 struct metapage *mp;
955 xtpage_t *p;
956 s64 nextbn;
957 int skip, maxentry, middle, righthalf, n;
958 xad_t *xad;
959 struct pxdlist *pxdlist;
960 pxd_t *pxd;
961 struct tlock *tlck;
962 struct xtlock *sxtlck = NULL, *rxtlck = NULL;
963 int quota_allocation = 0;
964
965 smp = split->mp;
966 sp = XT_PAGE(ip, smp);
967
968 INCREMENT(xtStat.split);
969
970 pxdlist = split->pxdlist;
971 pxd = &pxdlist->pxd[pxdlist->npxd];
972 pxdlist->npxd++;
973 rbn = addressPXD(pxd);
974
975 /* Allocate blocks to quota. */
976 rc = dquot_alloc_block(ip, lengthPXD(pxd));
977 if (rc)
978 goto clean_up;
979
980 quota_allocation += lengthPXD(pxd);
981
982 /*
983 * allocate the new right page for the split
984 */
985 rmp = get_metapage(ip, rbn, PSIZE, 1);
986 if (rmp == NULL) {
987 rc = -EIO;
988 goto clean_up;
989 }
990
991 jfs_info("xtSplitPage: ip:0x%p smp:0x%p rmp:0x%p", ip, smp, rmp);
992
993 BT_MARK_DIRTY(rmp, ip);
994 /*
995 * action: new page;
996 */
997
998 rp = (xtpage_t *) rmp->data;
999 rp->header.self = *pxd;
1000 rp->header.flag = sp->header.flag & BT_TYPE;
1001 rp->header.maxentry = sp->header.maxentry; /* little-endian */
1002 rp->header.nextindex = cpu_to_le16(XTENTRYSTART);
1003
1004 BT_MARK_DIRTY(smp, ip);
1005 /* Don't log it if there are no links to the file */
1006 if (!test_cflag(COMMIT_Nolink, ip)) {
1007 /*
1008 * acquire a transaction lock on the new right page;
1009 */
1010 tlck = txLock(tid, ip, rmp, tlckXTREE | tlckNEW);
1011 rxtlck = (struct xtlock *) & tlck->lock;
1012 rxtlck->lwm.offset = XTENTRYSTART;
1013 /*
1014 * acquire a transaction lock on the split page
1015 */
1016 tlck = txLock(tid, ip, smp, tlckXTREE | tlckGROW);
1017 sxtlck = (struct xtlock *) & tlck->lock;
1018 }
1019
1020 /*
1021 * initialize/update sibling pointers of <sp> and <rp>
1022 */
1023 nextbn = le64_to_cpu(sp->header.next);
1024 rp->header.next = cpu_to_le64(nextbn);
1025 rp->header.prev = cpu_to_le64(addressPXD(&sp->header.self));
1026 sp->header.next = cpu_to_le64(rbn);
1027
1028 skip = split->index;
1029
1030 /*
1031 * sequential append at tail (after last entry of last page)
1032 *
1033 * if splitting the last page on a level because of appending
1034 * a entry to it (skip is maxentry), it's likely that the access is
1035 * sequential. adding an empty page on the side of the level is less
1036 * work and can push the fill factor much higher than normal.
1037 * if we're wrong it's no big deal - we will do the split the right
1038 * way next time.
1039 * (it may look like it's equally easy to do a similar hack for
1040 * reverse sorted data, that is, split the tree left, but it's not.
1041 * Be my guest.)
1042 */
1043 if (nextbn == 0 && skip == le16_to_cpu(sp->header.maxentry)) {
1044 /*
1045 * acquire a transaction lock on the new/right page;
1046 *
1047 * action: xad insertion;
1048 */
1049 /* insert entry at the first entry of the new right page */
1050 xad = &rp->xad[XTENTRYSTART];
1051 XT_PUTENTRY(xad, split->flag, split->off, split->len,
1052 split->addr);
1053
1054 rp->header.nextindex = cpu_to_le16(XTENTRYSTART + 1);
1055
1056 if (!test_cflag(COMMIT_Nolink, ip)) {
1057 /* rxtlck->lwm.offset = XTENTRYSTART; */
1058 rxtlck->lwm.length = 1;
1059 }
1060
1061 *rmpp = rmp;
1062 *rbnp = rbn;
1063
1064 jfs_info("xtSplitPage: sp:0x%p rp:0x%p", sp, rp);
1065 return 0;
1066 }
1067
1068 /*
1069 * non-sequential insert (at possibly middle page)
1070 */
1071
1072 /*
1073 * update previous pointer of old next/right page of <sp>
1074 */
1075 if (nextbn != 0) {
1076 XT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
1077 if (rc) {
1078 XT_PUTPAGE(rmp);
1079 goto clean_up;
1080 }
1081
1082 BT_MARK_DIRTY(mp, ip);
1083 /*
1084 * acquire a transaction lock on the next page;
1085 *
1086 * action:sibling pointer update;
1087 */
1088 if (!test_cflag(COMMIT_Nolink, ip))
1089 tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
1090
1091 p->header.prev = cpu_to_le64(rbn);
1092
1093 /* sibling page may have been updated previously, or
1094 * it may be updated later;
1095 */
1096
1097 XT_PUTPAGE(mp);
1098 }
1099
1100 /*
1101 * split the data between the split and new/right pages
1102 */
1103 maxentry = le16_to_cpu(sp->header.maxentry);
1104 middle = maxentry >> 1;
1105 righthalf = maxentry - middle;
1106
1107 /*
1108 * skip index in old split/left page - insert into left page:
1109 */
1110 if (skip <= middle) {
1111 /* move right half of split page to the new right page */
1112 memmove(&rp->xad[XTENTRYSTART], &sp->xad[middle],
1113 righthalf << L2XTSLOTSIZE);
1114
1115 /* shift right tail of left half to make room for new entry */
1116 if (skip < middle)
1117 memmove(&sp->xad[skip + 1], &sp->xad[skip],
1118 (middle - skip) << L2XTSLOTSIZE);
1119
1120 /* insert new entry */
1121 xad = &sp->xad[skip];
1122 XT_PUTENTRY(xad, split->flag, split->off, split->len,
1123 split->addr);
1124
1125 /* update page header */
1126 sp->header.nextindex = cpu_to_le16(middle + 1);
1127 if (!test_cflag(COMMIT_Nolink, ip)) {
1128 sxtlck->lwm.offset = (sxtlck->lwm.offset) ?
1129 min(skip, (int)sxtlck->lwm.offset) : skip;
1130 }
1131
1132 rp->header.nextindex =
1133 cpu_to_le16(XTENTRYSTART + righthalf);
1134 }
1135 /*
1136 * skip index in new right page - insert into right page:
1137 */
1138 else {
1139 /* move left head of right half to right page */
1140 n = skip - middle;
1141 memmove(&rp->xad[XTENTRYSTART], &sp->xad[middle],
1142 n << L2XTSLOTSIZE);
1143
1144 /* insert new entry */
1145 n += XTENTRYSTART;
1146 xad = &rp->xad[n];
1147 XT_PUTENTRY(xad, split->flag, split->off, split->len,
1148 split->addr);
1149
1150 /* move right tail of right half to right page */
1151 if (skip < maxentry)
1152 memmove(&rp->xad[n + 1], &sp->xad[skip],
1153 (maxentry - skip) << L2XTSLOTSIZE);
1154
1155 /* update page header */
1156 sp->header.nextindex = cpu_to_le16(middle);
1157 if (!test_cflag(COMMIT_Nolink, ip)) {
1158 sxtlck->lwm.offset = (sxtlck->lwm.offset) ?
1159 min(middle, (int)sxtlck->lwm.offset) : middle;
1160 }
1161
1162 rp->header.nextindex = cpu_to_le16(XTENTRYSTART +
1163 righthalf + 1);
1164 }
1165
1166 if (!test_cflag(COMMIT_Nolink, ip)) {
1167 sxtlck->lwm.length = le16_to_cpu(sp->header.nextindex) -
1168 sxtlck->lwm.offset;
1169
1170 /* rxtlck->lwm.offset = XTENTRYSTART; */
1171 rxtlck->lwm.length = le16_to_cpu(rp->header.nextindex) -
1172 XTENTRYSTART;
1173 }
1174
1175 *rmpp = rmp;
1176 *rbnp = rbn;
1177
1178 jfs_info("xtSplitPage: sp:0x%p rp:0x%p", sp, rp);
1179 return rc;
1180
1181 clean_up:
1182
1183 /* Rollback quota allocation. */
1184 if (quota_allocation)
1185 dquot_free_block(ip, quota_allocation);
1186
1187 return (rc);
1188 }
1189
1190
1191 /*
1192 * xtSplitRoot()
1193 *
1194 * function:
1195 * split the full root page into original/root/split page and new
1196 * right page
1197 * i.e., root remains fixed in tree anchor (inode) and the root is
1198 * copied to a single new right child page since root page <<
1199 * non-root page, and the split root page contains a single entry
1200 * for the new right child page.
1201 *
1202 * parameter:
1203 * int tid,
1204 * struct inode *ip,
1205 * struct xtsplit *split,
1206 * struct metapage **rmpp)
1207 *
1208 * return:
1209 * Pointer to page in which to insert or NULL on error.
1210 */
1211 static int
1212 xtSplitRoot(tid_t tid,
1213 struct inode *ip, struct xtsplit * split, struct metapage ** rmpp)
1214 {
1215 xtpage_t *sp;
1216 struct metapage *rmp;
1217 xtpage_t *rp;
1218 s64 rbn;
1219 int skip, nextindex;
1220 xad_t *xad;
1221 pxd_t *pxd;
1222 struct pxdlist *pxdlist;
1223 struct tlock *tlck;
1224 struct xtlock *xtlck;
1225 int rc;
1226
1227 sp = &JFS_IP(ip)->i_xtroot;
1228
1229 INCREMENT(xtStat.split);
1230
1231 /*
1232 * allocate a single (right) child page
1233 */
1234 pxdlist = split->pxdlist;
1235 pxd = &pxdlist->pxd[pxdlist->npxd];
1236 pxdlist->npxd++;
1237 rbn = addressPXD(pxd);
1238 rmp = get_metapage(ip, rbn, PSIZE, 1);
1239 if (rmp == NULL)
1240 return -EIO;
1241
1242 /* Allocate blocks to quota. */
1243 rc = dquot_alloc_block(ip, lengthPXD(pxd));
1244 if (rc) {
1245 release_metapage(rmp);
1246 return rc;
1247 }
1248
1249 jfs_info("xtSplitRoot: ip:0x%p rmp:0x%p", ip, rmp);
1250
1251 /*
1252 * acquire a transaction lock on the new right page;
1253 *
1254 * action: new page;
1255 */
1256 BT_MARK_DIRTY(rmp, ip);
1257
1258 rp = (xtpage_t *) rmp->data;
1259 rp->header.flag =
1260 (sp->header.flag & BT_LEAF) ? BT_LEAF : BT_INTERNAL;
1261 rp->header.self = *pxd;
1262 rp->header.nextindex = cpu_to_le16(XTENTRYSTART);
1263 rp->header.maxentry = cpu_to_le16(PSIZE >> L2XTSLOTSIZE);
1264
1265 /* initialize sibling pointers */
1266 rp->header.next = 0;
1267 rp->header.prev = 0;
1268
1269 /*
1270 * copy the in-line root page into new right page extent
1271 */
1272 nextindex = le16_to_cpu(sp->header.maxentry);
1273 memmove(&rp->xad[XTENTRYSTART], &sp->xad[XTENTRYSTART],
1274 (nextindex - XTENTRYSTART) << L2XTSLOTSIZE);
1275
1276 /*
1277 * insert the new entry into the new right/child page
1278 * (skip index in the new right page will not change)
1279 */
1280 skip = split->index;
1281 /* if insert into middle, shift right remaining entries */
1282 if (skip != nextindex)
1283 memmove(&rp->xad[skip + 1], &rp->xad[skip],
1284 (nextindex - skip) * sizeof(xad_t));
1285
1286 xad = &rp->xad[skip];
1287 XT_PUTENTRY(xad, split->flag, split->off, split->len, split->addr);
1288
1289 /* update page header */
1290 rp->header.nextindex = cpu_to_le16(nextindex + 1);
1291
1292 if (!test_cflag(COMMIT_Nolink, ip)) {
1293 tlck = txLock(tid, ip, rmp, tlckXTREE | tlckNEW);
1294 xtlck = (struct xtlock *) & tlck->lock;
1295 xtlck->lwm.offset = XTENTRYSTART;
1296 xtlck->lwm.length = le16_to_cpu(rp->header.nextindex) -
1297 XTENTRYSTART;
1298 }
1299
1300 /*
1301 * reset the root
1302 *
1303 * init root with the single entry for the new right page
1304 * set the 1st entry offset to 0, which force the left-most key
1305 * at any level of the tree to be less than any search key.
1306 */
1307 /*
1308 * acquire a transaction lock on the root page (in-memory inode);
1309 *
1310 * action: root split;
1311 */
1312 BT_MARK_DIRTY(split->mp, ip);
1313
1314 xad = &sp->xad[XTENTRYSTART];
1315 XT_PUTENTRY(xad, XAD_NEW, 0, JFS_SBI(ip->i_sb)->nbperpage, rbn);
1316
1317 /* update page header of root */
1318 sp->header.flag &= ~BT_LEAF;
1319 sp->header.flag |= BT_INTERNAL;
1320
1321 sp->header.nextindex = cpu_to_le16(XTENTRYSTART + 1);
1322
1323 if (!test_cflag(COMMIT_Nolink, ip)) {
1324 tlck = txLock(tid, ip, split->mp, tlckXTREE | tlckGROW);
1325 xtlck = (struct xtlock *) & tlck->lock;
1326 xtlck->lwm.offset = XTENTRYSTART;
1327 xtlck->lwm.length = 1;
1328 }
1329
1330 *rmpp = rmp;
1331
1332 jfs_info("xtSplitRoot: sp:0x%p rp:0x%p", sp, rp);
1333 return 0;
1334 }
1335
1336
1337 /*
1338 * xtExtend()
1339 *
1340 * function: extend in-place;
1341 *
1342 * note: existing extent may or may not have been committed.
1343 * caller is responsible for pager buffer cache update, and
1344 * working block allocation map update;
1345 * update pmap: alloc whole extended extent;
1346 */
1347 int xtExtend(tid_t tid, /* transaction id */
1348 struct inode *ip, s64 xoff, /* delta extent offset */
1349 s32 xlen, /* delta extent length */
1350 int flag)
1351 {
1352 int rc = 0;
1353 int cmp;
1354 struct metapage *mp; /* meta-page buffer */
1355 xtpage_t *p; /* base B+-tree index page */
1356 s64 bn;
1357 int index, nextindex, len;
1358 struct btstack btstack; /* traverse stack */
1359 struct xtsplit split; /* split information */
1360 xad_t *xad;
1361 s64 xaddr;
1362 struct tlock *tlck;
1363 struct xtlock *xtlck = NULL;
1364
1365 jfs_info("xtExtend: nxoff:0x%lx nxlen:0x%x", (ulong) xoff, xlen);
1366
1367 /* there must exist extent to be extended */
1368 if ((rc = xtSearch(ip, xoff - 1, NULL, &cmp, &btstack, XT_INSERT)))
1369 return rc;
1370
1371 /* retrieve search result */
1372 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
1373
1374 if (cmp != 0) {
1375 XT_PUTPAGE(mp);
1376 jfs_error(ip->i_sb, "xtSearch did not find extent\n");
1377 return -EIO;
1378 }
1379
1380 /* extension must be contiguous */
1381 xad = &p->xad[index];
1382 if ((offsetXAD(xad) + lengthXAD(xad)) != xoff) {
1383 XT_PUTPAGE(mp);
1384 jfs_error(ip->i_sb, "extension is not contiguous\n");
1385 return -EIO;
1386 }
1387
1388 /*
1389 * acquire a transaction lock on the leaf page;
1390 *
1391 * action: xad insertion/extension;
1392 */
1393 BT_MARK_DIRTY(mp, ip);
1394 if (!test_cflag(COMMIT_Nolink, ip)) {
1395 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
1396 xtlck = (struct xtlock *) & tlck->lock;
1397 }
1398
1399 /* extend will overflow extent ? */
1400 xlen = lengthXAD(xad) + xlen;
1401 if ((len = xlen - MAXXLEN) <= 0)
1402 goto extendOld;
1403
1404 /*
1405 * extent overflow: insert entry for new extent
1406 */
1407 //insertNew:
1408 xoff = offsetXAD(xad) + MAXXLEN;
1409 xaddr = addressXAD(xad) + MAXXLEN;
1410 nextindex = le16_to_cpu(p->header.nextindex);
1411
1412 /*
1413 * if the leaf page is full, insert the new entry and
1414 * propagate up the router entry for the new page from split
1415 *
1416 * The xtSplitUp() will insert the entry and unpin the leaf page.
1417 */
1418 if (nextindex == le16_to_cpu(p->header.maxentry)) {
1419 /* xtSpliUp() unpins leaf pages */
1420 split.mp = mp;
1421 split.index = index + 1;
1422 split.flag = XAD_NEW;
1423 split.off = xoff; /* split offset */
1424 split.len = len;
1425 split.addr = xaddr;
1426 split.pxdlist = NULL;
1427 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
1428 return rc;
1429
1430 /* get back old page */
1431 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1432 if (rc)
1433 return rc;
1434 /*
1435 * if leaf root has been split, original root has been
1436 * copied to new child page, i.e., original entry now
1437 * resides on the new child page;
1438 */
1439 if (p->header.flag & BT_INTERNAL) {
1440 ASSERT(p->header.nextindex ==
1441 cpu_to_le16(XTENTRYSTART + 1));
1442 xad = &p->xad[XTENTRYSTART];
1443 bn = addressXAD(xad);
1444 XT_PUTPAGE(mp);
1445
1446 /* get new child page */
1447 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1448 if (rc)
1449 return rc;
1450
1451 BT_MARK_DIRTY(mp, ip);
1452 if (!test_cflag(COMMIT_Nolink, ip)) {
1453 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
1454 xtlck = (struct xtlock *) & tlck->lock;
1455 }
1456 }
1457 }
1458 /*
1459 * insert the new entry into the leaf page
1460 */
1461 else {
1462 /* insert the new entry: mark the entry NEW */
1463 xad = &p->xad[index + 1];
1464 XT_PUTENTRY(xad, XAD_NEW, xoff, len, xaddr);
1465
1466 /* advance next available entry index */
1467 le16_add_cpu(&p->header.nextindex, 1);
1468 }
1469
1470 /* get back old entry */
1471 xad = &p->xad[index];
1472 xlen = MAXXLEN;
1473
1474 /*
1475 * extend old extent
1476 */
1477 extendOld:
1478 XADlength(xad, xlen);
1479 if (!(xad->flag & XAD_NEW))
1480 xad->flag |= XAD_EXTENDED;
1481
1482 if (!test_cflag(COMMIT_Nolink, ip)) {
1483 xtlck->lwm.offset =
1484 (xtlck->lwm.offset) ? min(index,
1485 (int)xtlck->lwm.offset) : index;
1486 xtlck->lwm.length =
1487 le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
1488 }
1489
1490 /* unpin the leaf page */
1491 XT_PUTPAGE(mp);
1492
1493 return rc;
1494 }
1495
1496 #ifdef _NOTYET
1497 /*
1498 * xtTailgate()
1499 *
1500 * function: split existing 'tail' extent
1501 * (split offset >= start offset of tail extent), and
1502 * relocate and extend the split tail half;
1503 *
1504 * note: existing extent may or may not have been committed.
1505 * caller is responsible for pager buffer cache update, and
1506 * working block allocation map update;
1507 * update pmap: free old split tail extent, alloc new extent;
1508 */
1509 int xtTailgate(tid_t tid, /* transaction id */
1510 struct inode *ip, s64 xoff, /* split/new extent offset */
1511 s32 xlen, /* new extent length */
1512 s64 xaddr, /* new extent address */
1513 int flag)
1514 {
1515 int rc = 0;
1516 int cmp;
1517 struct metapage *mp; /* meta-page buffer */
1518 xtpage_t *p; /* base B+-tree index page */
1519 s64 bn;
1520 int index, nextindex, llen, rlen;
1521 struct btstack btstack; /* traverse stack */
1522 struct xtsplit split; /* split information */
1523 xad_t *xad;
1524 struct tlock *tlck;
1525 struct xtlock *xtlck = 0;
1526 struct tlock *mtlck;
1527 struct maplock *pxdlock;
1528
1529 /*
1530 printf("xtTailgate: nxoff:0x%lx nxlen:0x%x nxaddr:0x%lx\n",
1531 (ulong)xoff, xlen, (ulong)xaddr);
1532 */
1533
1534 /* there must exist extent to be tailgated */
1535 if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, XT_INSERT)))
1536 return rc;
1537
1538 /* retrieve search result */
1539 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
1540
1541 if (cmp != 0) {
1542 XT_PUTPAGE(mp);
1543 jfs_error(ip->i_sb, "couldn't find extent\n");
1544 return -EIO;
1545 }
1546
1547 /* entry found must be last entry */
1548 nextindex = le16_to_cpu(p->header.nextindex);
1549 if (index != nextindex - 1) {
1550 XT_PUTPAGE(mp);
1551 jfs_error(ip->i_sb, "the entry found is not the last entry\n");
1552 return -EIO;
1553 }
1554
1555 BT_MARK_DIRTY(mp, ip);
1556 /*
1557 * acquire tlock of the leaf page containing original entry
1558 */
1559 if (!test_cflag(COMMIT_Nolink, ip)) {
1560 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
1561 xtlck = (struct xtlock *) & tlck->lock;
1562 }
1563
1564 /* completely replace extent ? */
1565 xad = &p->xad[index];
1566 /*
1567 printf("xtTailgate: xoff:0x%lx xlen:0x%x xaddr:0x%lx\n",
1568 (ulong)offsetXAD(xad), lengthXAD(xad), (ulong)addressXAD(xad));
1569 */
1570 if ((llen = xoff - offsetXAD(xad)) == 0)
1571 goto updateOld;
1572
1573 /*
1574 * partially replace extent: insert entry for new extent
1575 */
1576 //insertNew:
1577 /*
1578 * if the leaf page is full, insert the new entry and
1579 * propagate up the router entry for the new page from split
1580 *
1581 * The xtSplitUp() will insert the entry and unpin the leaf page.
1582 */
1583 if (nextindex == le16_to_cpu(p->header.maxentry)) {
1584 /* xtSpliUp() unpins leaf pages */
1585 split.mp = mp;
1586 split.index = index + 1;
1587 split.flag = XAD_NEW;
1588 split.off = xoff; /* split offset */
1589 split.len = xlen;
1590 split.addr = xaddr;
1591 split.pxdlist = NULL;
1592 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
1593 return rc;
1594
1595 /* get back old page */
1596 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1597 if (rc)
1598 return rc;
1599 /*
1600 * if leaf root has been split, original root has been
1601 * copied to new child page, i.e., original entry now
1602 * resides on the new child page;
1603 */
1604 if (p->header.flag & BT_INTERNAL) {
1605 ASSERT(p->header.nextindex ==
1606 cpu_to_le16(XTENTRYSTART + 1));
1607 xad = &p->xad[XTENTRYSTART];
1608 bn = addressXAD(xad);
1609 XT_PUTPAGE(mp);
1610
1611 /* get new child page */
1612 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1613 if (rc)
1614 return rc;
1615
1616 BT_MARK_DIRTY(mp, ip);
1617 if (!test_cflag(COMMIT_Nolink, ip)) {
1618 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
1619 xtlck = (struct xtlock *) & tlck->lock;
1620 }
1621 }
1622 }
1623 /*
1624 * insert the new entry into the leaf page
1625 */
1626 else {
1627 /* insert the new entry: mark the entry NEW */
1628 xad = &p->xad[index + 1];
1629 XT_PUTENTRY(xad, XAD_NEW, xoff, xlen, xaddr);
1630
1631 /* advance next available entry index */
1632 le16_add_cpu(&p->header.nextindex, 1);
1633 }
1634
1635 /* get back old XAD */
1636 xad = &p->xad[index];
1637
1638 /*
1639 * truncate/relocate old extent at split offset
1640 */
1641 updateOld:
1642 /* update dmap for old/committed/truncated extent */
1643 rlen = lengthXAD(xad) - llen;
1644 if (!(xad->flag & XAD_NEW)) {
1645 /* free from PWMAP at commit */
1646 if (!test_cflag(COMMIT_Nolink, ip)) {
1647 mtlck = txMaplock(tid, ip, tlckMAP);
1648 pxdlock = (struct maplock *) & mtlck->lock;
1649 pxdlock->flag = mlckFREEPXD;
1650 PXDaddress(&pxdlock->pxd, addressXAD(xad) + llen);
1651 PXDlength(&pxdlock->pxd, rlen);
1652 pxdlock->index = 1;
1653 }
1654 } else
1655 /* free from WMAP */
1656 dbFree(ip, addressXAD(xad) + llen, (s64) rlen);
1657
1658 if (llen)
1659 /* truncate */
1660 XADlength(xad, llen);
1661 else
1662 /* replace */
1663 XT_PUTENTRY(xad, XAD_NEW, xoff, xlen, xaddr);
1664
1665 if (!test_cflag(COMMIT_Nolink, ip)) {
1666 xtlck->lwm.offset = (xtlck->lwm.offset) ?
1667 min(index, (int)xtlck->lwm.offset) : index;
1668 xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
1669 xtlck->lwm.offset;
1670 }
1671
1672 /* unpin the leaf page */
1673 XT_PUTPAGE(mp);
1674
1675 return rc;
1676 }
1677 #endif /* _NOTYET */
1678
1679 /*
1680 * xtUpdate()
1681 *
1682 * function: update XAD;
1683 *
1684 * update extent for allocated_but_not_recorded or
1685 * compressed extent;
1686 *
1687 * parameter:
1688 * nxad - new XAD;
1689 * logical extent of the specified XAD must be completely
1690 * contained by an existing XAD;
1691 */
1692 int xtUpdate(tid_t tid, struct inode *ip, xad_t * nxad)
1693 { /* new XAD */
1694 int rc = 0;
1695 int cmp;
1696 struct metapage *mp; /* meta-page buffer */
1697 xtpage_t *p; /* base B+-tree index page */
1698 s64 bn;
1699 int index0, index, newindex, nextindex;
1700 struct btstack btstack; /* traverse stack */
1701 struct xtsplit split; /* split information */
1702 xad_t *xad, *lxad, *rxad;
1703 int xflag;
1704 s64 nxoff, xoff;
1705 int nxlen, xlen, lxlen, rxlen;
1706 s64 nxaddr, xaddr;
1707 struct tlock *tlck;
1708 struct xtlock *xtlck = NULL;
1709 int newpage = 0;
1710
1711 /* there must exist extent to be tailgated */
1712 nxoff = offsetXAD(nxad);
1713 nxlen = lengthXAD(nxad);
1714 nxaddr = addressXAD(nxad);
1715
1716 if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
1717 return rc;
1718
1719 /* retrieve search result */
1720 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index0);
1721
1722 if (cmp != 0) {
1723 XT_PUTPAGE(mp);
1724 jfs_error(ip->i_sb, "Could not find extent\n");
1725 return -EIO;
1726 }
1727
1728 BT_MARK_DIRTY(mp, ip);
1729 /*
1730 * acquire tlock of the leaf page containing original entry
1731 */
1732 if (!test_cflag(COMMIT_Nolink, ip)) {
1733 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
1734 xtlck = (struct xtlock *) & tlck->lock;
1735 }
1736
1737 xad = &p->xad[index0];
1738 xflag = xad->flag;
1739 xoff = offsetXAD(xad);
1740 xlen = lengthXAD(xad);
1741 xaddr = addressXAD(xad);
1742
1743 /* nXAD must be completely contained within XAD */
1744 if ((xoff > nxoff) ||
1745 (nxoff + nxlen > xoff + xlen)) {
1746 XT_PUTPAGE(mp);
1747 jfs_error(ip->i_sb,
1748 "nXAD in not completely contained within XAD\n");
1749 return -EIO;
1750 }
1751
1752 index = index0;
1753 newindex = index + 1;
1754 nextindex = le16_to_cpu(p->header.nextindex);
1755
1756 #ifdef _JFS_WIP_NOCOALESCE
1757 if (xoff < nxoff)
1758 goto updateRight;
1759
1760 /*
1761 * replace XAD with nXAD
1762 */
1763 replace: /* (nxoff == xoff) */
1764 if (nxlen == xlen) {
1765 /* replace XAD with nXAD:recorded */
1766 *xad = *nxad;
1767 xad->flag = xflag & ~XAD_NOTRECORDED;
1768
1769 goto out;
1770 } else /* (nxlen < xlen) */
1771 goto updateLeft;
1772 #endif /* _JFS_WIP_NOCOALESCE */
1773
1774 /* #ifdef _JFS_WIP_COALESCE */
1775 if (xoff < nxoff)
1776 goto coalesceRight;
1777
1778 /*
1779 * coalesce with left XAD
1780 */
1781 //coalesceLeft: /* (xoff == nxoff) */
1782 /* is XAD first entry of page ? */
1783 if (index == XTENTRYSTART)
1784 goto replace;
1785
1786 /* is nXAD logically and physically contiguous with lXAD ? */
1787 lxad = &p->xad[index - 1];
1788 lxlen = lengthXAD(lxad);
1789 if (!(lxad->flag & XAD_NOTRECORDED) &&
1790 (nxoff == offsetXAD(lxad) + lxlen) &&
1791 (nxaddr == addressXAD(lxad) + lxlen) &&
1792 (lxlen + nxlen < MAXXLEN)) {
1793 /* extend right lXAD */
1794 index0 = index - 1;
1795 XADlength(lxad, lxlen + nxlen);
1796
1797 /* If we just merged two extents together, need to make sure the
1798 * right extent gets logged. If the left one is marked XAD_NEW,
1799 * then we know it will be logged. Otherwise, mark as
1800 * XAD_EXTENDED
1801 */
1802 if (!(lxad->flag & XAD_NEW))
1803 lxad->flag |= XAD_EXTENDED;
1804
1805 if (xlen > nxlen) {
1806 /* truncate XAD */
1807 XADoffset(xad, xoff + nxlen);
1808 XADlength(xad, xlen - nxlen);
1809 XADaddress(xad, xaddr + nxlen);
1810 goto out;
1811 } else { /* (xlen == nxlen) */
1812
1813 /* remove XAD */
1814 if (index < nextindex - 1)
1815 memmove(&p->xad[index], &p->xad[index + 1],
1816 (nextindex - index -
1817 1) << L2XTSLOTSIZE);
1818
1819 p->header.nextindex =
1820 cpu_to_le16(le16_to_cpu(p->header.nextindex) -
1821 1);
1822
1823 index = index0;
1824 newindex = index + 1;
1825 nextindex = le16_to_cpu(p->header.nextindex);
1826 xoff = nxoff = offsetXAD(lxad);
1827 xlen = nxlen = lxlen + nxlen;
1828 xaddr = nxaddr = addressXAD(lxad);
1829 goto coalesceRight;
1830 }
1831 }
1832
1833 /*
1834 * replace XAD with nXAD
1835 */
1836 replace: /* (nxoff == xoff) */
1837 if (nxlen == xlen) {
1838 /* replace XAD with nXAD:recorded */
1839 *xad = *nxad;
1840 xad->flag = xflag & ~XAD_NOTRECORDED;
1841
1842 goto coalesceRight;
1843 } else /* (nxlen < xlen) */
1844 goto updateLeft;
1845
1846 /*
1847 * coalesce with right XAD
1848 */
1849 coalesceRight: /* (xoff <= nxoff) */
1850 /* is XAD last entry of page ? */
1851 if (newindex == nextindex) {
1852 if (xoff == nxoff)
1853 goto out;
1854 goto updateRight;
1855 }
1856
1857 /* is nXAD logically and physically contiguous with rXAD ? */
1858 rxad = &p->xad[index + 1];
1859 rxlen = lengthXAD(rxad);
1860 if (!(rxad->flag & XAD_NOTRECORDED) &&
1861 (nxoff + nxlen == offsetXAD(rxad)) &&
1862 (nxaddr + nxlen == addressXAD(rxad)) &&
1863 (rxlen + nxlen < MAXXLEN)) {
1864 /* extend left rXAD */
1865 XADoffset(rxad, nxoff);
1866 XADlength(rxad, rxlen + nxlen);
1867 XADaddress(rxad, nxaddr);
1868
1869 /* If we just merged two extents together, need to make sure
1870 * the left extent gets logged. If the right one is marked
1871 * XAD_NEW, then we know it will be logged. Otherwise, mark as
1872 * XAD_EXTENDED
1873 */
1874 if (!(rxad->flag & XAD_NEW))
1875 rxad->flag |= XAD_EXTENDED;
1876
1877 if (xlen > nxlen)
1878 /* truncate XAD */
1879 XADlength(xad, xlen - nxlen);
1880 else { /* (xlen == nxlen) */
1881
1882 /* remove XAD */
1883 memmove(&p->xad[index], &p->xad[index + 1],
1884 (nextindex - index - 1) << L2XTSLOTSIZE);
1885
1886 p->header.nextindex =
1887 cpu_to_le16(le16_to_cpu(p->header.nextindex) -
1888 1);
1889 }
1890
1891 goto out;
1892 } else if (xoff == nxoff)
1893 goto out;
1894
1895 if (xoff >= nxoff) {
1896 XT_PUTPAGE(mp);
1897 jfs_error(ip->i_sb, "xoff >= nxoff\n");
1898 return -EIO;
1899 }
1900 /* #endif _JFS_WIP_COALESCE */
1901
1902 /*
1903 * split XAD into (lXAD, nXAD):
1904 *
1905 * |---nXAD--->
1906 * --|----------XAD----------|--
1907 * |-lXAD-|
1908 */
1909 updateRight: /* (xoff < nxoff) */
1910 /* truncate old XAD as lXAD:not_recorded */
1911 xad = &p->xad[index];
1912 XADlength(xad, nxoff - xoff);
1913
1914 /* insert nXAD:recorded */
1915 if (nextindex == le16_to_cpu(p->header.maxentry)) {
1916
1917 /* xtSpliUp() unpins leaf pages */
1918 split.mp = mp;
1919 split.index = newindex;
1920 split.flag = xflag & ~XAD_NOTRECORDED;
1921 split.off = nxoff;
1922 split.len = nxlen;
1923 split.addr = nxaddr;
1924 split.pxdlist = NULL;
1925 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
1926 return rc;
1927
1928 /* get back old page */
1929 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1930 if (rc)
1931 return rc;
1932 /*
1933 * if leaf root has been split, original root has been
1934 * copied to new child page, i.e., original entry now
1935 * resides on the new child page;
1936 */
1937 if (p->header.flag & BT_INTERNAL) {
1938 ASSERT(p->header.nextindex ==
1939 cpu_to_le16(XTENTRYSTART + 1));
1940 xad = &p->xad[XTENTRYSTART];
1941 bn = addressXAD(xad);
1942 XT_PUTPAGE(mp);
1943
1944 /* get new child page */
1945 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
1946 if (rc)
1947 return rc;
1948
1949 BT_MARK_DIRTY(mp, ip);
1950 if (!test_cflag(COMMIT_Nolink, ip)) {
1951 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
1952 xtlck = (struct xtlock *) & tlck->lock;
1953 }
1954 } else {
1955 /* is nXAD on new page ? */
1956 if (newindex >
1957 (le16_to_cpu(p->header.maxentry) >> 1)) {
1958 newindex =
1959 newindex -
1960 le16_to_cpu(p->header.nextindex) +
1961 XTENTRYSTART;
1962 newpage = 1;
1963 }
1964 }
1965 } else {
1966 /* if insert into middle, shift right remaining entries */
1967 if (newindex < nextindex)
1968 memmove(&p->xad[newindex + 1], &p->xad[newindex],
1969 (nextindex - newindex) << L2XTSLOTSIZE);
1970
1971 /* insert the entry */
1972 xad = &p->xad[newindex];
1973 *xad = *nxad;
1974 xad->flag = xflag & ~XAD_NOTRECORDED;
1975
1976 /* advance next available entry index. */
1977 p->header.nextindex =
1978 cpu_to_le16(le16_to_cpu(p->header.nextindex) + 1);
1979 }
1980
1981 /*
1982 * does nXAD force 3-way split ?
1983 *
1984 * |---nXAD--->|
1985 * --|----------XAD-------------|--
1986 * |-lXAD-| |-rXAD -|
1987 */
1988 if (nxoff + nxlen == xoff + xlen)
1989 goto out;
1990
1991 /* reorient nXAD as XAD for further split XAD into (nXAD, rXAD) */
1992 if (newpage) {
1993 /* close out old page */
1994 if (!test_cflag(COMMIT_Nolink, ip)) {
1995 xtlck->lwm.offset = (xtlck->lwm.offset) ?
1996 min(index0, (int)xtlck->lwm.offset) : index0;
1997 xtlck->lwm.length =
1998 le16_to_cpu(p->header.nextindex) -
1999 xtlck->lwm.offset;
2000 }
2001
2002 bn = le64_to_cpu(p->header.next);
2003 XT_PUTPAGE(mp);
2004
2005 /* get new right page */
2006 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2007 if (rc)
2008 return rc;
2009
2010 BT_MARK_DIRTY(mp, ip);
2011 if (!test_cflag(COMMIT_Nolink, ip)) {
2012 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
2013 xtlck = (struct xtlock *) & tlck->lock;
2014 }
2015
2016 index0 = index = newindex;
2017 } else
2018 index++;
2019
2020 newindex = index + 1;
2021 nextindex = le16_to_cpu(p->header.nextindex);
2022 xlen = xlen - (nxoff - xoff);
2023 xoff = nxoff;
2024 xaddr = nxaddr;
2025
2026 /* recompute split pages */
2027 if (nextindex == le16_to_cpu(p->header.maxentry)) {
2028 XT_PUTPAGE(mp);
2029
2030 if ((rc = xtSearch(ip, nxoff, NULL, &cmp, &btstack, XT_INSERT)))
2031 return rc;
2032
2033 /* retrieve search result */
2034 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index0);
2035
2036 if (cmp != 0) {
2037 XT_PUTPAGE(mp);
2038 jfs_error(ip->i_sb, "xtSearch failed\n");
2039 return -EIO;
2040 }
2041
2042 if (index0 != index) {
2043 XT_PUTPAGE(mp);
2044 jfs_error(ip->i_sb, "unexpected value of index\n");
2045 return -EIO;
2046 }
2047 }
2048
2049 /*
2050 * split XAD into (nXAD, rXAD)
2051 *
2052 * ---nXAD---|
2053 * --|----------XAD----------|--
2054 * |-rXAD-|
2055 */
2056 updateLeft: /* (nxoff == xoff) && (nxlen < xlen) */
2057 /* update old XAD with nXAD:recorded */
2058 xad = &p->xad[index];
2059 *xad = *nxad;
2060 xad->flag = xflag & ~XAD_NOTRECORDED;
2061
2062 /* insert rXAD:not_recorded */
2063 xoff = xoff + nxlen;
2064 xlen = xlen - nxlen;
2065 xaddr = xaddr + nxlen;
2066 if (nextindex == le16_to_cpu(p->header.maxentry)) {
2067 /*
2068 printf("xtUpdate.updateLeft.split p:0x%p\n", p);
2069 */
2070 /* xtSpliUp() unpins leaf pages */
2071 split.mp = mp;
2072 split.index = newindex;
2073 split.flag = xflag;
2074 split.off = xoff;
2075 split.len = xlen;
2076 split.addr = xaddr;
2077 split.pxdlist = NULL;
2078 if ((rc = xtSplitUp(tid, ip, &split, &btstack)))
2079 return rc;
2080
2081 /* get back old page */
2082 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2083 if (rc)
2084 return rc;
2085
2086 /*
2087 * if leaf root has been split, original root has been
2088 * copied to new child page, i.e., original entry now
2089 * resides on the new child page;
2090 */
2091 if (p->header.flag & BT_INTERNAL) {
2092 ASSERT(p->header.nextindex ==
2093 cpu_to_le16(XTENTRYSTART + 1));
2094 xad = &p->xad[XTENTRYSTART];
2095 bn = addressXAD(xad);
2096 XT_PUTPAGE(mp);
2097
2098 /* get new child page */
2099 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2100 if (rc)
2101 return rc;
2102
2103 BT_MARK_DIRTY(mp, ip);
2104 if (!test_cflag(COMMIT_Nolink, ip)) {
2105 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
2106 xtlck = (struct xtlock *) & tlck->lock;
2107 }
2108 }
2109 } else {
2110 /* if insert into middle, shift right remaining entries */
2111 if (newindex < nextindex)
2112 memmove(&p->xad[newindex + 1], &p->xad[newindex],
2113 (nextindex - newindex) << L2XTSLOTSIZE);
2114
2115 /* insert the entry */
2116 xad = &p->xad[newindex];
2117 XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
2118
2119 /* advance next available entry index. */
2120 p->header.nextindex =
2121 cpu_to_le16(le16_to_cpu(p->header.nextindex) + 1);
2122 }
2123
2124 out:
2125 if (!test_cflag(COMMIT_Nolink, ip)) {
2126 xtlck->lwm.offset = (xtlck->lwm.offset) ?
2127 min(index0, (int)xtlck->lwm.offset) : index0;
2128 xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
2129 xtlck->lwm.offset;
2130 }
2131
2132 /* unpin the leaf page */
2133 XT_PUTPAGE(mp);
2134
2135 return rc;
2136 }
2137
2138
2139 /*
2140 * xtAppend()
2141 *
2142 * function: grow in append mode from contiguous region specified ;
2143 *
2144 * parameter:
2145 * tid - transaction id;
2146 * ip - file object;
2147 * xflag - extent flag:
2148 * xoff - extent offset;
2149 * maxblocks - max extent length;
2150 * xlen - extent length (in/out);
2151 * xaddrp - extent address pointer (in/out):
2152 * flag -
2153 *
2154 * return:
2155 */
2156 int xtAppend(tid_t tid, /* transaction id */
2157 struct inode *ip, int xflag, s64 xoff, s32 maxblocks,
2158 s32 * xlenp, /* (in/out) */
2159 s64 * xaddrp, /* (in/out) */
2160 int flag)
2161 {
2162 int rc = 0;
2163 struct metapage *mp; /* meta-page buffer */
2164 xtpage_t *p; /* base B+-tree index page */
2165 s64 bn, xaddr;
2166 int index, nextindex;
2167 struct btstack btstack; /* traverse stack */
2168 struct xtsplit split; /* split information */
2169 xad_t *xad;
2170 int cmp;
2171 struct tlock *tlck;
2172 struct xtlock *xtlck;
2173 int nsplit, nblocks, xlen;
2174 struct pxdlist pxdlist;
2175 pxd_t *pxd;
2176 s64 next;
2177
2178 xaddr = *xaddrp;
2179 xlen = *xlenp;
2180 jfs_info("xtAppend: xoff:0x%lx maxblocks:%d xlen:%d xaddr:0x%lx",
2181 (ulong) xoff, maxblocks, xlen, (ulong) xaddr);
2182
2183 /*
2184 * search for the entry location at which to insert:
2185 *
2186 * xtFastSearch() and xtSearch() both returns (leaf page
2187 * pinned, index at which to insert).
2188 * n.b. xtSearch() may return index of maxentry of
2189 * the full page.
2190 */
2191 if ((rc = xtSearch(ip, xoff, &next, &cmp, &btstack, XT_INSERT)))
2192 return rc;
2193
2194 /* retrieve search result */
2195 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
2196
2197 if (cmp == 0) {
2198 rc = -EEXIST;
2199 goto out;
2200 }
2201
2202 if (next)
2203 xlen = min(xlen, (int)(next - xoff));
2204 //insert:
2205 /*
2206 * insert entry for new extent
2207 */
2208 xflag |= XAD_NEW;
2209
2210 /*
2211 * if the leaf page is full, split the page and
2212 * propagate up the router entry for the new page from split
2213 *
2214 * The xtSplitUp() will insert the entry and unpin the leaf page.
2215 */
2216 nextindex = le16_to_cpu(p->header.nextindex);
2217 if (nextindex < le16_to_cpu(p->header.maxentry))
2218 goto insertLeaf;
2219
2220 /*
2221 * allocate new index blocks to cover index page split(s)
2222 */
2223 nsplit = btstack.nsplit;
2224 split.pxdlist = &pxdlist;
2225 pxdlist.maxnpxd = pxdlist.npxd = 0;
2226 pxd = &pxdlist.pxd[0];
2227 nblocks = JFS_SBI(ip->i_sb)->nbperpage;
2228 for (; nsplit > 0; nsplit--, pxd++, xaddr += nblocks, maxblocks -= nblocks) {
2229 if ((rc = dbAllocBottomUp(ip, xaddr, (s64) nblocks)) == 0) {
2230 PXDaddress(pxd, xaddr);
2231 PXDlength(pxd, nblocks);
2232
2233 pxdlist.maxnpxd++;
2234
2235 continue;
2236 }
2237
2238 /* undo allocation */
2239
2240 goto out;
2241 }
2242
2243 xlen = min(xlen, maxblocks);
2244
2245 /*
2246 * allocate data extent requested
2247 */
2248 if ((rc = dbAllocBottomUp(ip, xaddr, (s64) xlen)))
2249 goto out;
2250
2251 split.mp = mp;
2252 split.index = index;
2253 split.flag = xflag;
2254 split.off = xoff;
2255 split.len = xlen;
2256 split.addr = xaddr;
2257 if ((rc = xtSplitUp(tid, ip, &split, &btstack))) {
2258 /* undo data extent allocation */
2259 dbFree(ip, *xaddrp, (s64) * xlenp);
2260
2261 return rc;
2262 }
2263
2264 *xaddrp = xaddr;
2265 *xlenp = xlen;
2266 return 0;
2267
2268 /*
2269 * insert the new entry into the leaf page
2270 */
2271 insertLeaf:
2272 /*
2273 * allocate data extent requested
2274 */
2275 if ((rc = dbAllocBottomUp(ip, xaddr, (s64) xlen)))
2276 goto out;
2277
2278 BT_MARK_DIRTY(mp, ip);
2279 /*
2280 * acquire a transaction lock on the leaf page;
2281 *
2282 * action: xad insertion/extension;
2283 */
2284 tlck = txLock(tid, ip, mp, tlckXTREE | tlckGROW);
2285 xtlck = (struct xtlock *) & tlck->lock;
2286
2287 /* insert the new entry: mark the entry NEW */
2288 xad = &p->xad[index];
2289 XT_PUTENTRY(xad, xflag, xoff, xlen, xaddr);
2290
2291 /* advance next available entry index */
2292 le16_add_cpu(&p->header.nextindex, 1);
2293
2294 xtlck->lwm.offset =
2295 (xtlck->lwm.offset) ? min(index,(int) xtlck->lwm.offset) : index;
2296 xtlck->lwm.length = le16_to_cpu(p->header.nextindex) -
2297 xtlck->lwm.offset;
2298
2299 *xaddrp = xaddr;
2300 *xlenp = xlen;
2301
2302 out:
2303 /* unpin the leaf page */
2304 XT_PUTPAGE(mp);
2305
2306 return rc;
2307 }
2308 #ifdef _STILL_TO_PORT
2309
2310 /* - TBD for defragmentaion/reorganization -
2311 *
2312 * xtDelete()
2313 *
2314 * function:
2315 * delete the entry with the specified key.
2316 *
2317 * N.B.: whole extent of the entry is assumed to be deleted.
2318 *
2319 * parameter:
2320 *
2321 * return:
2322 * ENOENT: if the entry is not found.
2323 *
2324 * exception:
2325 */
2326 int xtDelete(tid_t tid, struct inode *ip, s64 xoff, s32 xlen, int flag)
2327 {
2328 int rc = 0;
2329 struct btstack btstack;
2330 int cmp;
2331 s64 bn;
2332 struct metapage *mp;
2333 xtpage_t *p;
2334 int index, nextindex;
2335 struct tlock *tlck;
2336 struct xtlock *xtlck;
2337
2338 /*
2339 * find the matching entry; xtSearch() pins the page
2340 */
2341 if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
2342 return rc;
2343
2344 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
2345 if (cmp) {
2346 /* unpin the leaf page */
2347 XT_PUTPAGE(mp);
2348 return -ENOENT;
2349 }
2350
2351 /*
2352 * delete the entry from the leaf page
2353 */
2354 nextindex = le16_to_cpu(p->header.nextindex);
2355 le16_add_cpu(&p->header.nextindex, -1);
2356
2357 /*
2358 * if the leaf page bocome empty, free the page
2359 */
2360 if (p->header.nextindex == cpu_to_le16(XTENTRYSTART))
2361 return (xtDeleteUp(tid, ip, mp, p, &btstack));
2362
2363 BT_MARK_DIRTY(mp, ip);
2364 /*
2365 * acquire a transaction lock on the leaf page;
2366 *
2367 * action:xad deletion;
2368 */
2369 tlck = txLock(tid, ip, mp, tlckXTREE);
2370 xtlck = (struct xtlock *) & tlck->lock;
2371 xtlck->lwm.offset =
2372 (xtlck->lwm.offset) ? min(index, xtlck->lwm.offset) : index;
2373
2374 /* if delete from middle, shift left/compact the remaining entries */
2375 if (index < nextindex - 1)
2376 memmove(&p->xad[index], &p->xad[index + 1],
2377 (nextindex - index - 1) * sizeof(xad_t));
2378
2379 XT_PUTPAGE(mp);
2380
2381 return 0;
2382 }
2383
2384
2385 /* - TBD for defragmentaion/reorganization -
2386 *
2387 * xtDeleteUp()
2388 *
2389 * function:
2390 * free empty pages as propagating deletion up the tree
2391 *
2392 * parameter:
2393 *
2394 * return:
2395 */
2396 static int
2397 xtDeleteUp(tid_t tid, struct inode *ip,
2398 struct metapage * fmp, xtpage_t * fp, struct btstack * btstack)
2399 {
2400 int rc = 0;
2401 struct metapage *mp;
2402 xtpage_t *p;
2403 int index, nextindex;
2404 s64 xaddr;
2405 int xlen;
2406 struct btframe *parent;
2407 struct tlock *tlck;
2408 struct xtlock *xtlck;
2409
2410 /*
2411 * keep root leaf page which has become empty
2412 */
2413 if (fp->header.flag & BT_ROOT) {
2414 /* keep the root page */
2415 fp->header.flag &= ~BT_INTERNAL;
2416 fp->header.flag |= BT_LEAF;
2417 fp->header.nextindex = cpu_to_le16(XTENTRYSTART);
2418
2419 /* XT_PUTPAGE(fmp); */
2420
2421 return 0;
2422 }
2423
2424 /*
2425 * free non-root leaf page
2426 */
2427 if ((rc = xtRelink(tid, ip, fp))) {
2428 XT_PUTPAGE(fmp);
2429 return rc;
2430 }
2431
2432 xaddr = addressPXD(&fp->header.self);
2433 xlen = lengthPXD(&fp->header.self);
2434 /* free the page extent */
2435 dbFree(ip, xaddr, (s64) xlen);
2436
2437 /* free the buffer page */
2438 discard_metapage(fmp);
2439
2440 /*
2441 * propagate page deletion up the index tree
2442 *
2443 * If the delete from the parent page makes it empty,
2444 * continue all the way up the tree.
2445 * stop if the root page is reached (which is never deleted) or
2446 * if the entry deletion does not empty the page.
2447 */
2448 while ((parent = BT_POP(btstack)) != NULL) {
2449 /* get/pin the parent page <sp> */
2450 XT_GETPAGE(ip, parent->bn, mp, PSIZE, p, rc);
2451 if (rc)
2452 return rc;
2453
2454 index = parent->index;
2455
2456 /* delete the entry for the freed child page from parent.
2457 */
2458 nextindex = le16_to_cpu(p->header.nextindex);
2459
2460 /*
2461 * the parent has the single entry being deleted:
2462 * free the parent page which has become empty.
2463 */
2464 if (nextindex == 1) {
2465 if (p->header.flag & BT_ROOT) {
2466 /* keep the root page */
2467 p->header.flag &= ~BT_INTERNAL;
2468 p->header.flag |= BT_LEAF;
2469 p->header.nextindex =
2470 cpu_to_le16(XTENTRYSTART);
2471
2472 /* XT_PUTPAGE(mp); */
2473
2474 break;
2475 } else {
2476 /* free the parent page */
2477 if ((rc = xtRelink(tid, ip, p)))
2478 return rc;
2479
2480 xaddr = addressPXD(&p->header.self);
2481 /* free the page extent */
2482 dbFree(ip, xaddr,
2483 (s64) JFS_SBI(ip->i_sb)->nbperpage);
2484
2485 /* unpin/free the buffer page */
2486 discard_metapage(mp);
2487
2488 /* propagate up */
2489 continue;
2490 }
2491 }
2492 /*
2493 * the parent has other entries remaining:
2494 * delete the router entry from the parent page.
2495 */
2496 else {
2497 BT_MARK_DIRTY(mp, ip);
2498 /*
2499 * acquire a transaction lock on the leaf page;
2500 *
2501 * action:xad deletion;
2502 */
2503 tlck = txLock(tid, ip, mp, tlckXTREE);
2504 xtlck = (struct xtlock *) & tlck->lock;
2505 xtlck->lwm.offset =
2506 (xtlck->lwm.offset) ? min(index,
2507 xtlck->lwm.
2508 offset) : index;
2509
2510 /* if delete from middle,
2511 * shift left/compact the remaining entries in the page
2512 */
2513 if (index < nextindex - 1)
2514 memmove(&p->xad[index], &p->xad[index + 1],
2515 (nextindex - index -
2516 1) << L2XTSLOTSIZE);
2517
2518 le16_add_cpu(&p->header.nextindex, -1);
2519 jfs_info("xtDeleteUp(entry): 0x%lx[%d]",
2520 (ulong) parent->bn, index);
2521 }
2522
2523 /* unpin the parent page */
2524 XT_PUTPAGE(mp);
2525
2526 /* exit propagation up */
2527 break;
2528 }
2529
2530 return 0;
2531 }
2532
2533
2534 /*
2535 * NAME: xtRelocate()
2536 *
2537 * FUNCTION: relocate xtpage or data extent of regular file;
2538 * This function is mainly used by defragfs utility.
2539 *
2540 * NOTE: This routine does not have the logic to handle
2541 * uncommitted allocated extent. The caller should call
2542 * txCommit() to commit all the allocation before call
2543 * this routine.
2544 */
2545 int
2546 xtRelocate(tid_t tid, struct inode * ip, xad_t * oxad, /* old XAD */
2547 s64 nxaddr, /* new xaddr */
2548 int xtype)
2549 { /* extent type: XTPAGE or DATAEXT */
2550 int rc = 0;
2551 struct tblock *tblk;
2552 struct tlock *tlck;
2553 struct xtlock *xtlck;
2554 struct metapage *mp, *pmp, *lmp, *rmp; /* meta-page buffer */
2555 xtpage_t *p, *pp, *rp, *lp; /* base B+-tree index page */
2556 xad_t *xad;
2557 pxd_t *pxd;
2558 s64 xoff, xsize;
2559 int xlen;
2560 s64 oxaddr, sxaddr, dxaddr, nextbn, prevbn;
2561 cbuf_t *cp;
2562 s64 offset, nbytes, nbrd, pno;
2563 int nb, npages, nblks;
2564 s64 bn;
2565 int cmp;
2566 int index;
2567 struct pxd_lock *pxdlock;
2568 struct btstack btstack; /* traverse stack */
2569
2570 xtype = xtype & EXTENT_TYPE;
2571
2572 xoff = offsetXAD(oxad);
2573 oxaddr = addressXAD(oxad);
2574 xlen = lengthXAD(oxad);
2575
2576 /* validate extent offset */
2577 offset = xoff << JFS_SBI(ip->i_sb)->l2bsize;
2578 if (offset >= ip->i_size)
2579 return -ESTALE; /* stale extent */
2580
2581 jfs_info("xtRelocate: xtype:%d xoff:0x%lx xlen:0x%x xaddr:0x%lx:0x%lx",
2582 xtype, (ulong) xoff, xlen, (ulong) oxaddr, (ulong) nxaddr);
2583
2584 /*
2585 * 1. get and validate the parent xtpage/xad entry
2586 * covering the source extent to be relocated;
2587 */
2588 if (xtype == DATAEXT) {
2589 /* search in leaf entry */
2590 rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
2591 if (rc)
2592 return rc;
2593
2594 /* retrieve search result */
2595 XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2596
2597 if (cmp) {
2598 XT_PUTPAGE(pmp);
2599 return -ESTALE;
2600 }
2601
2602 /* validate for exact match with a single entry */
2603 xad = &pp->xad[index];
2604 if (addressXAD(xad) != oxaddr || lengthXAD(xad) != xlen) {
2605 XT_PUTPAGE(pmp);
2606 return -ESTALE;
2607 }
2608 } else { /* (xtype == XTPAGE) */
2609
2610 /* search in internal entry */
2611 rc = xtSearchNode(ip, oxad, &cmp, &btstack, 0);
2612 if (rc)
2613 return rc;
2614
2615 /* retrieve search result */
2616 XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2617
2618 if (cmp) {
2619 XT_PUTPAGE(pmp);
2620 return -ESTALE;
2621 }
2622
2623 /* xtSearchNode() validated for exact match with a single entry
2624 */
2625 xad = &pp->xad[index];
2626 }
2627 jfs_info("xtRelocate: parent xad entry validated.");
2628
2629 /*
2630 * 2. relocate the extent
2631 */
2632 if (xtype == DATAEXT) {
2633 /* if the extent is allocated-but-not-recorded
2634 * there is no real data to be moved in this extent,
2635 */
2636 if (xad->flag & XAD_NOTRECORDED)
2637 goto out;
2638 else
2639 /* release xtpage for cmRead()/xtLookup() */
2640 XT_PUTPAGE(pmp);
2641
2642 /*
2643 * cmRelocate()
2644 *
2645 * copy target data pages to be relocated;
2646 *
2647 * data extent must start at page boundary and
2648 * multiple of page size (except the last data extent);
2649 * read in each page of the source data extent into cbuf,
2650 * update the cbuf extent descriptor of the page to be
2651 * homeward bound to new dst data extent
2652 * copy the data from the old extent to new extent.
2653 * copy is essential for compressed files to avoid problems
2654 * that can arise if there was a change in compression
2655 * algorithms.
2656 * it is a good strategy because it may disrupt cache
2657 * policy to keep the pages in memory afterwards.
2658 */
2659 offset = xoff << JFS_SBI(ip->i_sb)->l2bsize;
2660 assert((offset & CM_OFFSET) == 0);
2661 nbytes = xlen << JFS_SBI(ip->i_sb)->l2bsize;
2662 pno = offset >> CM_L2BSIZE;
2663 npages = (nbytes + (CM_BSIZE - 1)) >> CM_L2BSIZE;
2664 /*
2665 npages = ((offset + nbytes - 1) >> CM_L2BSIZE) -
2666 (offset >> CM_L2BSIZE) + 1;
2667 */
2668 sxaddr = oxaddr;
2669 dxaddr = nxaddr;
2670
2671 /* process the request one cache buffer at a time */
2672 for (nbrd = 0; nbrd < nbytes; nbrd += nb,
2673 offset += nb, pno++, npages--) {
2674 /* compute page size */
2675 nb = min(nbytes - nbrd, CM_BSIZE);
2676
2677 /* get the cache buffer of the page */
2678 if (rc = cmRead(ip, offset, npages, &cp))
2679 break;
2680
2681 assert(addressPXD(&cp->cm_pxd) == sxaddr);
2682 assert(!cp->cm_modified);
2683
2684 /* bind buffer with the new extent address */
2685 nblks = nb >> JFS_IP(ip->i_sb)->l2bsize;
2686 cmSetXD(ip, cp, pno, dxaddr, nblks);
2687
2688 /* release the cbuf, mark it as modified */
2689 cmPut(cp, true);
2690
2691 dxaddr += nblks;
2692 sxaddr += nblks;
2693 }
2694
2695 /* get back parent page */
2696 if ((rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0)))
2697 return rc;
2698
2699 XT_GETSEARCH(ip, btstack.top, bn, pmp, pp, index);
2700 jfs_info("xtRelocate: target data extent relocated.");
2701 } else { /* (xtype == XTPAGE) */
2702
2703 /*
2704 * read in the target xtpage from the source extent;
2705 */
2706 XT_GETPAGE(ip, oxaddr, mp, PSIZE, p, rc);
2707 if (rc) {
2708 XT_PUTPAGE(pmp);
2709 return rc;
2710 }
2711
2712 /*
2713 * read in sibling pages if any to update sibling pointers;
2714 */
2715 rmp = NULL;
2716 if (p->header.next) {
2717 nextbn = le64_to_cpu(p->header.next);
2718 XT_GETPAGE(ip, nextbn, rmp, PSIZE, rp, rc);
2719 if (rc) {
2720 XT_PUTPAGE(pmp);
2721 XT_PUTPAGE(mp);
2722 return (rc);
2723 }
2724 }
2725
2726 lmp = NULL;
2727 if (p->header.prev) {
2728 prevbn = le64_to_cpu(p->header.prev);
2729 XT_GETPAGE(ip, prevbn, lmp, PSIZE, lp, rc);
2730 if (rc) {
2731 XT_PUTPAGE(pmp);
2732 XT_PUTPAGE(mp);
2733 if (rmp)
2734 XT_PUTPAGE(rmp);
2735 return (rc);
2736 }
2737 }
2738
2739 /* at this point, all xtpages to be updated are in memory */
2740
2741 /*
2742 * update sibling pointers of sibling xtpages if any;
2743 */
2744 if (lmp) {
2745 BT_MARK_DIRTY(lmp, ip);
2746 tlck = txLock(tid, ip, lmp, tlckXTREE | tlckRELINK);
2747 lp->header.next = cpu_to_le64(nxaddr);
2748 XT_PUTPAGE(lmp);
2749 }
2750
2751 if (rmp) {
2752 BT_MARK_DIRTY(rmp, ip);
2753 tlck = txLock(tid, ip, rmp, tlckXTREE | tlckRELINK);
2754 rp->header.prev = cpu_to_le64(nxaddr);
2755 XT_PUTPAGE(rmp);
2756 }
2757
2758 /*
2759 * update the target xtpage to be relocated
2760 *
2761 * update the self address of the target page
2762 * and write to destination extent;
2763 * redo image covers the whole xtpage since it is new page
2764 * to the destination extent;
2765 * update of bmap for the free of source extent
2766 * of the target xtpage itself:
2767 * update of bmap for the allocation of destination extent
2768 * of the target xtpage itself:
2769 * update of bmap for the extents covered by xad entries in
2770 * the target xtpage is not necessary since they are not
2771 * updated;
2772 * if not committed before this relocation,
2773 * target page may contain XAD_NEW entries which must
2774 * be scanned for bmap update (logredo() always
2775 * scan xtpage REDOPAGE image for bmap update);
2776 * if committed before this relocation (tlckRELOCATE),
2777 * scan may be skipped by commit() and logredo();
2778 */
2779 BT_MARK_DIRTY(mp, ip);
2780 /* tlckNEW init xtlck->lwm.offset = XTENTRYSTART; */
2781 tlck = txLock(tid, ip, mp, tlckXTREE | tlckNEW);
2782 xtlck = (struct xtlock *) & tlck->lock;
2783
2784 /* update the self address in the xtpage header */
2785 pxd = &p->header.self;
2786 PXDaddress(pxd, nxaddr);
2787
2788 /* linelock for the after image of the whole page */
2789 xtlck->lwm.length =
2790 le16_to_cpu(p->header.nextindex) - xtlck->lwm.offset;
2791
2792 /* update the buffer extent descriptor of target xtpage */
2793 xsize = xlen << JFS_SBI(ip->i_sb)->l2bsize;
2794 bmSetXD(mp, nxaddr, xsize);
2795
2796 /* unpin the target page to new homeward bound */
2797 XT_PUTPAGE(mp);
2798 jfs_info("xtRelocate: target xtpage relocated.");
2799 }
2800
2801 /*
2802 * 3. acquire maplock for the source extent to be freed;
2803 *
2804 * acquire a maplock saving the src relocated extent address;
2805 * to free of the extent at commit time;
2806 */
2807 out:
2808 /* if DATAEXT relocation, write a LOG_UPDATEMAP record for
2809 * free PXD of the source data extent (logredo() will update
2810 * bmap for free of source data extent), and update bmap for
2811 * free of the source data extent;
2812 */
2813 if (xtype == DATAEXT)
2814 tlck = txMaplock(tid, ip, tlckMAP);
2815 /* if XTPAGE relocation, write a LOG_NOREDOPAGE record
2816 * for the source xtpage (logredo() will init NoRedoPage
2817 * filter and will also update bmap for free of the source
2818 * xtpage), and update bmap for free of the source xtpage;
2819 * N.B. We use tlckMAP instead of tlkcXTREE because there
2820 * is no buffer associated with this lock since the buffer
2821 * has been redirected to the target location.
2822 */
2823 else /* (xtype == XTPAGE) */
2824 tlck = txMaplock(tid, ip, tlckMAP | tlckRELOCATE);
2825
2826 pxdlock = (struct pxd_lock *) & tlck->lock;
2827 pxdlock->flag = mlckFREEPXD;
2828 PXDaddress(&pxdlock->pxd, oxaddr);
2829 PXDlength(&pxdlock->pxd, xlen);
2830 pxdlock->index = 1;
2831
2832 /*
2833 * 4. update the parent xad entry for relocation;
2834 *
2835 * acquire tlck for the parent entry with XAD_NEW as entry
2836 * update which will write LOG_REDOPAGE and update bmap for
2837 * allocation of XAD_NEW destination extent;
2838 */
2839 jfs_info("xtRelocate: update parent xad entry.");
2840 BT_MARK_DIRTY(pmp, ip);
2841 tlck = txLock(tid, ip, pmp, tlckXTREE | tlckGROW);
2842 xtlck = (struct xtlock *) & tlck->lock;
2843
2844 /* update the XAD with the new destination extent; */
2845 xad = &pp->xad[index];
2846 xad->flag |= XAD_NEW;
2847 XADaddress(xad, nxaddr);
2848
2849 xtlck->lwm.offset = min(index, xtlck->lwm.offset);
2850 xtlck->lwm.length = le16_to_cpu(pp->header.nextindex) -
2851 xtlck->lwm.offset;
2852
2853 /* unpin the parent xtpage */
2854 XT_PUTPAGE(pmp);
2855
2856 return rc;
2857 }
2858
2859
2860 /*
2861 * xtSearchNode()
2862 *
2863 * function: search for the internal xad entry covering specified extent.
2864 * This function is mainly used by defragfs utility.
2865 *
2866 * parameters:
2867 * ip - file object;
2868 * xad - extent to find;
2869 * cmpp - comparison result:
2870 * btstack - traverse stack;
2871 * flag - search process flag;
2872 *
2873 * returns:
2874 * btstack contains (bn, index) of search path traversed to the entry.
2875 * *cmpp is set to result of comparison with the entry returned.
2876 * the page containing the entry is pinned at exit.
2877 */
2878 static int xtSearchNode(struct inode *ip, xad_t * xad, /* required XAD entry */
2879 int *cmpp, struct btstack * btstack, int flag)
2880 {
2881 int rc = 0;
2882 s64 xoff, xaddr;
2883 int xlen;
2884 int cmp = 1; /* init for empty page */
2885 s64 bn; /* block number */
2886 struct metapage *mp; /* meta-page buffer */
2887 xtpage_t *p; /* page */
2888 int base, index, lim;
2889 struct btframe *btsp;
2890 s64 t64;
2891
2892 BT_CLR(btstack);
2893
2894 xoff = offsetXAD(xad);
2895 xlen = lengthXAD(xad);
2896 xaddr = addressXAD(xad);
2897
2898 /*
2899 * search down tree from root:
2900 *
2901 * between two consecutive entries of <Ki, Pi> and <Kj, Pj> of
2902 * internal page, child page Pi contains entry with k, Ki <= K < Kj.
2903 *
2904 * if entry with search key K is not found
2905 * internal page search find the entry with largest key Ki
2906 * less than K which point to the child page to search;
2907 * leaf page search find the entry with smallest key Kj
2908 * greater than K so that the returned index is the position of
2909 * the entry to be shifted right for insertion of new entry.
2910 * for empty tree, search key is greater than any key of the tree.
2911 *
2912 * by convention, root bn = 0.
2913 */
2914 for (bn = 0;;) {
2915 /* get/pin the page to search */
2916 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
2917 if (rc)
2918 return rc;
2919 if (p->header.flag & BT_LEAF) {
2920 XT_PUTPAGE(mp);
2921 return -ESTALE;
2922 }
2923
2924 lim = le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
2925
2926 /*
2927 * binary search with search key K on the current page
2928 */
2929 for (base = XTENTRYSTART; lim; lim >>= 1) {
2930 index = base + (lim >> 1);
2931
2932 XT_CMP(cmp, xoff, &p->xad[index], t64);
2933 if (cmp == 0) {
2934 /*
2935 * search hit
2936 *
2937 * verify for exact match;
2938 */
2939 if (xaddr == addressXAD(&p->xad[index]) &&
2940 xoff == offsetXAD(&p->xad[index])) {
2941 *cmpp = cmp;
2942
2943 /* save search result */
2944 btsp = btstack->top;
2945 btsp->bn = bn;
2946 btsp->index = index;
2947 btsp->mp = mp;
2948
2949 return 0;
2950 }
2951
2952 /* descend/search its child page */
2953 goto next;
2954 }
2955
2956 if (cmp > 0) {
2957 base = index + 1;
2958 --lim;
2959 }
2960 }
2961
2962 /*
2963 * search miss - non-leaf page:
2964 *
2965 * base is the smallest index with key (Kj) greater than
2966 * search key (K) and may be zero or maxentry index.
2967 * if base is non-zero, decrement base by one to get the parent
2968 * entry of the child page to search.
2969 */
2970 index = base ? base - 1 : base;
2971
2972 /*
2973 * go down to child page
2974 */
2975 next:
2976 /* get the child page block number */
2977 bn = addressXAD(&p->xad[index]);
2978
2979 /* unpin the parent page */
2980 XT_PUTPAGE(mp);
2981 }
2982 }
2983
2984
2985 /*
2986 * xtRelink()
2987 *
2988 * function:
2989 * link around a freed page.
2990 *
2991 * Parameter:
2992 * int tid,
2993 * struct inode *ip,
2994 * xtpage_t *p)
2995 *
2996 * returns:
2997 */
2998 static int xtRelink(tid_t tid, struct inode *ip, xtpage_t * p)
2999 {
3000 int rc = 0;
3001 struct metapage *mp;
3002 s64 nextbn, prevbn;
3003 struct tlock *tlck;
3004
3005 nextbn = le64_to_cpu(p->header.next);
3006 prevbn = le64_to_cpu(p->header.prev);
3007
3008 /* update prev pointer of the next page */
3009 if (nextbn != 0) {
3010 XT_GETPAGE(ip, nextbn, mp, PSIZE, p, rc);
3011 if (rc)
3012 return rc;
3013
3014 /*
3015 * acquire a transaction lock on the page;
3016 *
3017 * action: update prev pointer;
3018 */
3019 BT_MARK_DIRTY(mp, ip);
3020 tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
3021
3022 /* the page may already have been tlock'd */
3023
3024 p->header.prev = cpu_to_le64(prevbn);
3025
3026 XT_PUTPAGE(mp);
3027 }
3028
3029 /* update next pointer of the previous page */
3030 if (prevbn != 0) {
3031 XT_GETPAGE(ip, prevbn, mp, PSIZE, p, rc);
3032 if (rc)
3033 return rc;
3034
3035 /*
3036 * acquire a transaction lock on the page;
3037 *
3038 * action: update next pointer;
3039 */
3040 BT_MARK_DIRTY(mp, ip);
3041 tlck = txLock(tid, ip, mp, tlckXTREE | tlckRELINK);
3042
3043 /* the page may already have been tlock'd */
3044
3045 p->header.next = le64_to_cpu(nextbn);
3046
3047 XT_PUTPAGE(mp);
3048 }
3049
3050 return 0;
3051 }
3052 #endif /* _STILL_TO_PORT */
3053
3054
3055 /*
3056 * xtInitRoot()
3057 *
3058 * initialize file root (inline in inode)
3059 */
3060 void xtInitRoot(tid_t tid, struct inode *ip)
3061 {
3062 xtpage_t *p;
3063
3064 /*
3065 * acquire a transaction lock on the root
3066 *
3067 * action:
3068 */
3069 txLock(tid, ip, (struct metapage *) &JFS_IP(ip)->bxflag,
3070 tlckXTREE | tlckNEW);
3071 p = &JFS_IP(ip)->i_xtroot;
3072
3073 p->header.flag = DXD_INDEX | BT_ROOT | BT_LEAF;
3074 p->header.nextindex = cpu_to_le16(XTENTRYSTART);
3075
3076 if (S_ISDIR(ip->i_mode))
3077 p->header.maxentry = cpu_to_le16(XTROOTINITSLOT_DIR);
3078 else {
3079 p->header.maxentry = cpu_to_le16(XTROOTINITSLOT);
3080 ip->i_size = 0;
3081 }
3082
3083
3084 return;
3085 }
3086
3087
3088 /*
3089 * We can run into a deadlock truncating a file with a large number of
3090 * xtree pages (large fragmented file). A robust fix would entail a
3091 * reservation system where we would reserve a number of metadata pages
3092 * and tlocks which we would be guaranteed without a deadlock. Without
3093 * this, a partial fix is to limit number of metadata pages we will lock
3094 * in a single transaction. Currently we will truncate the file so that
3095 * no more than 50 leaf pages will be locked. The caller of xtTruncate
3096 * will be responsible for ensuring that the current transaction gets
3097 * committed, and that subsequent transactions are created to truncate
3098 * the file further if needed.
3099 */
3100 #define MAX_TRUNCATE_LEAVES 50
3101
3102 /*
3103 * xtTruncate()
3104 *
3105 * function:
3106 * traverse for truncation logging backward bottom up;
3107 * terminate at the last extent entry at the current subtree
3108 * root page covering new down size.
3109 * truncation may occur within the last extent entry.
3110 *
3111 * parameter:
3112 * int tid,
3113 * struct inode *ip,
3114 * s64 newsize,
3115 * int type) {PWMAP, PMAP, WMAP; DELETE, TRUNCATE}
3116 *
3117 * return:
3118 *
3119 * note:
3120 * PWMAP:
3121 * 1. truncate (non-COMMIT_NOLINK file)
3122 * by jfs_truncate() or jfs_open(O_TRUNC):
3123 * xtree is updated;
3124 * 2. truncate index table of directory when last entry removed
3125 * map update via tlock at commit time;
3126 * PMAP:
3127 * Call xtTruncate_pmap instead
3128 * WMAP:
3129 * 1. remove (free zero link count) on last reference release
3130 * (pmap has been freed at commit zero link count);
3131 * 2. truncate (COMMIT_NOLINK file, i.e., tmp file):
3132 * xtree is updated;
3133 * map update directly at truncation time;
3134 *
3135 * if (DELETE)
3136 * no LOG_NOREDOPAGE is required (NOREDOFILE is sufficient);
3137 * else if (TRUNCATE)
3138 * must write LOG_NOREDOPAGE for deleted index page;
3139 *
3140 * pages may already have been tlocked by anonymous transactions
3141 * during file growth (i.e., write) before truncation;
3142 *
3143 * except last truncated entry, deleted entries remains as is
3144 * in the page (nextindex is updated) for other use
3145 * (e.g., log/update allocation map): this avoid copying the page
3146 * info but delay free of pages;
3147 *
3148 */
3149 s64 xtTruncate(tid_t tid, struct inode *ip, s64 newsize, int flag)
3150 {
3151 int rc = 0;
3152 s64 teof;
3153 struct metapage *mp;
3154 xtpage_t *p;
3155 s64 bn;
3156 int index, nextindex;
3157 xad_t *xad;
3158 s64 xoff, xaddr;
3159 int xlen, len, freexlen;
3160 struct btstack btstack;
3161 struct btframe *parent;
3162 struct tblock *tblk = NULL;
3163 struct tlock *tlck = NULL;
3164 struct xtlock *xtlck = NULL;
3165 struct xdlistlock xadlock; /* maplock for COMMIT_WMAP */
3166 struct pxd_lock *pxdlock; /* maplock for COMMIT_WMAP */
3167 s64 nfreed;
3168 int freed, log;
3169 int locked_leaves = 0;
3170
3171 /* save object truncation type */
3172 if (tid) {
3173 tblk = tid_to_tblock(tid);
3174 tblk->xflag |= flag;
3175 }
3176
3177 nfreed = 0;
3178
3179 flag &= COMMIT_MAP;
3180 assert(flag != COMMIT_PMAP);
3181
3182 if (flag == COMMIT_PWMAP)
3183 log = 1;
3184 else {
3185 log = 0;
3186 xadlock.flag = mlckFREEXADLIST;
3187 xadlock.index = 1;
3188 }
3189
3190 /*
3191 * if the newsize is not an integral number of pages,
3192 * the file between newsize and next page boundary will
3193 * be cleared.
3194 * if truncating into a file hole, it will cause
3195 * a full block to be allocated for the logical block.
3196 */
3197
3198 /*
3199 * release page blocks of truncated region <teof, eof>
3200 *
3201 * free the data blocks from the leaf index blocks.
3202 * delete the parent index entries corresponding to
3203 * the freed child data/index blocks.
3204 * free the index blocks themselves which aren't needed
3205 * in new sized file.
3206 *
3207 * index blocks are updated only if the blocks are to be
3208 * retained in the new sized file.
3209 * if type is PMAP, the data and index pages are NOT
3210 * freed, and the data and index blocks are NOT freed
3211 * from working map.
3212 * (this will allow continued access of data/index of
3213 * temporary file (zerolink count file truncated to zero-length)).
3214 */
3215 teof = (newsize + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
3216 JFS_SBI(ip->i_sb)->l2bsize;
3217
3218 /* clear stack */
3219 BT_CLR(&btstack);
3220
3221 /*
3222 * start with root
3223 *
3224 * root resides in the inode
3225 */
3226 bn = 0;
3227
3228 /*
3229 * first access of each page:
3230 */
3231 getPage:
3232 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3233 if (rc)
3234 return rc;
3235
3236 /* process entries backward from last index */
3237 index = le16_to_cpu(p->header.nextindex) - 1;
3238
3239
3240 /* Since this is the rightmost page at this level, and we may have
3241 * already freed a page that was formerly to the right, let's make
3242 * sure that the next pointer is zero.
3243 */
3244 if (p->header.next) {
3245 if (log)
3246 /*
3247 * Make sure this change to the header is logged.
3248 * If we really truncate this leaf, the flag
3249 * will be changed to tlckTRUNCATE
3250 */
3251 tlck = txLock(tid, ip, mp, tlckXTREE|tlckGROW);
3252 BT_MARK_DIRTY(mp, ip);
3253 p->header.next = 0;
3254 }
3255
3256 if (p->header.flag & BT_INTERNAL)
3257 goto getChild;
3258
3259 /*
3260 * leaf page
3261 */
3262 freed = 0;
3263
3264 /* does region covered by leaf page precede Teof ? */
3265 xad = &p->xad[index];
3266 xoff = offsetXAD(xad);
3267 xlen = lengthXAD(xad);
3268 if (teof >= xoff + xlen) {
3269 XT_PUTPAGE(mp);
3270 goto getParent;
3271 }
3272
3273 /* (re)acquire tlock of the leaf page */
3274 if (log) {
3275 if (++locked_leaves > MAX_TRUNCATE_LEAVES) {
3276 /*
3277 * We need to limit the size of the transaction
3278 * to avoid exhausting pagecache & tlocks
3279 */
3280 XT_PUTPAGE(mp);
3281 newsize = (xoff + xlen) << JFS_SBI(ip->i_sb)->l2bsize;
3282 goto getParent;
3283 }
3284 tlck = txLock(tid, ip, mp, tlckXTREE);
3285 tlck->type = tlckXTREE | tlckTRUNCATE;
3286 xtlck = (struct xtlock *) & tlck->lock;
3287 xtlck->hwm.offset = le16_to_cpu(p->header.nextindex) - 1;
3288 }
3289 BT_MARK_DIRTY(mp, ip);
3290
3291 /*
3292 * scan backward leaf page entries
3293 */
3294 for (; index >= XTENTRYSTART; index--) {
3295 xad = &p->xad[index];
3296 xoff = offsetXAD(xad);
3297 xlen = lengthXAD(xad);
3298 xaddr = addressXAD(xad);
3299
3300 /*
3301 * The "data" for a directory is indexed by the block
3302 * device's address space. This metadata must be invalidated
3303 * here
3304 */
3305 if (S_ISDIR(ip->i_mode) && (teof == 0))
3306 invalidate_xad_metapages(ip, *xad);
3307 /*
3308 * entry beyond eof: continue scan of current page
3309 * xad
3310 * ---|---=======------->
3311 * eof
3312 */
3313 if (teof < xoff) {
3314 nfreed += xlen;
3315 continue;
3316 }
3317
3318 /*
3319 * (xoff <= teof): last entry to be deleted from page;
3320 * If other entries remain in page: keep and update the page.
3321 */
3322
3323 /*
3324 * eof == entry_start: delete the entry
3325 * xad
3326 * -------|=======------->
3327 * eof
3328 *
3329 */
3330 if (teof == xoff) {
3331 nfreed += xlen;
3332
3333 if (index == XTENTRYSTART)
3334 break;
3335
3336 nextindex = index;
3337 }
3338 /*
3339 * eof within the entry: truncate the entry.
3340 * xad
3341 * -------===|===------->
3342 * eof
3343 */
3344 else if (teof < xoff + xlen) {
3345 /* update truncated entry */
3346 len = teof - xoff;
3347 freexlen = xlen - len;
3348 XADlength(xad, len);
3349
3350 /* save pxd of truncated extent in tlck */
3351 xaddr += len;
3352 if (log) { /* COMMIT_PWMAP */
3353 xtlck->lwm.offset = (xtlck->lwm.offset) ?
3354 min(index, (int)xtlck->lwm.offset) : index;
3355 xtlck->lwm.length = index + 1 -
3356 xtlck->lwm.offset;
3357 xtlck->twm.offset = index;
3358 pxdlock = (struct pxd_lock *) & xtlck->pxdlock;
3359 pxdlock->flag = mlckFREEPXD;
3360 PXDaddress(&pxdlock->pxd, xaddr);
3361 PXDlength(&pxdlock->pxd, freexlen);
3362 }
3363 /* free truncated extent */
3364 else { /* COMMIT_WMAP */
3365
3366 pxdlock = (struct pxd_lock *) & xadlock;
3367 pxdlock->flag = mlckFREEPXD;
3368 PXDaddress(&pxdlock->pxd, xaddr);
3369 PXDlength(&pxdlock->pxd, freexlen);
3370 txFreeMap(ip, pxdlock, NULL, COMMIT_WMAP);
3371
3372 /* reset map lock */
3373 xadlock.flag = mlckFREEXADLIST;
3374 }
3375
3376 /* current entry is new last entry; */
3377 nextindex = index + 1;
3378
3379 nfreed += freexlen;
3380 }
3381 /*
3382 * eof beyond the entry:
3383 * xad
3384 * -------=======---|--->
3385 * eof
3386 */
3387 else { /* (xoff + xlen < teof) */
3388
3389 nextindex = index + 1;
3390 }
3391
3392 if (nextindex < le16_to_cpu(p->header.nextindex)) {
3393 if (!log) { /* COMMIT_WAMP */
3394 xadlock.xdlist = &p->xad[nextindex];
3395 xadlock.count =
3396 le16_to_cpu(p->header.nextindex) -
3397 nextindex;
3398 txFreeMap(ip, (struct maplock *) & xadlock,
3399 NULL, COMMIT_WMAP);
3400 }
3401 p->header.nextindex = cpu_to_le16(nextindex);
3402 }
3403
3404 XT_PUTPAGE(mp);
3405
3406 /* assert(freed == 0); */
3407 goto getParent;
3408 } /* end scan of leaf page entries */
3409
3410 freed = 1;
3411
3412 /*
3413 * leaf page become empty: free the page if type != PMAP
3414 */
3415 if (log) { /* COMMIT_PWMAP */
3416 /* txCommit() with tlckFREE:
3417 * free data extents covered by leaf [XTENTRYSTART:hwm);
3418 * invalidate leaf if COMMIT_PWMAP;
3419 * if (TRUNCATE), will write LOG_NOREDOPAGE;
3420 */
3421 tlck->type = tlckXTREE | tlckFREE;
3422 } else { /* COMMIT_WAMP */
3423
3424 /* free data extents covered by leaf */
3425 xadlock.xdlist = &p->xad[XTENTRYSTART];
3426 xadlock.count =
3427 le16_to_cpu(p->header.nextindex) - XTENTRYSTART;
3428 txFreeMap(ip, (struct maplock *) & xadlock, NULL, COMMIT_WMAP);
3429 }
3430
3431 if (p->header.flag & BT_ROOT) {
3432 p->header.flag &= ~BT_INTERNAL;
3433 p->header.flag |= BT_LEAF;
3434 p->header.nextindex = cpu_to_le16(XTENTRYSTART);
3435
3436 XT_PUTPAGE(mp); /* debug */
3437 goto out;
3438 } else {
3439 if (log) { /* COMMIT_PWMAP */
3440 /* page will be invalidated at tx completion
3441 */
3442 XT_PUTPAGE(mp);
3443 } else { /* COMMIT_WMAP */
3444
3445 if (mp->lid)
3446 lid_to_tlock(mp->lid)->flag |= tlckFREELOCK;
3447
3448 /* invalidate empty leaf page */
3449 discard_metapage(mp);
3450 }
3451 }
3452
3453 /*
3454 * the leaf page become empty: delete the parent entry
3455 * for the leaf page if the parent page is to be kept
3456 * in the new sized file.
3457 */
3458
3459 /*
3460 * go back up to the parent page
3461 */
3462 getParent:
3463 /* pop/restore parent entry for the current child page */
3464 if ((parent = BT_POP(&btstack)) == NULL)
3465 /* current page must have been root */
3466 goto out;
3467
3468 /* get back the parent page */
3469 bn = parent->bn;
3470 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3471 if (rc)
3472 return rc;
3473
3474 index = parent->index;
3475
3476 /*
3477 * child page was not empty:
3478 */
3479 if (freed == 0) {
3480 /* has any entry deleted from parent ? */
3481 if (index < le16_to_cpu(p->header.nextindex) - 1) {
3482 /* (re)acquire tlock on the parent page */
3483 if (log) { /* COMMIT_PWMAP */
3484 /* txCommit() with tlckTRUNCATE:
3485 * free child extents covered by parent [);
3486 */
3487 tlck = txLock(tid, ip, mp, tlckXTREE);
3488 xtlck = (struct xtlock *) & tlck->lock;
3489 if (!(tlck->type & tlckTRUNCATE)) {
3490 xtlck->hwm.offset =
3491 le16_to_cpu(p->header.
3492 nextindex) - 1;
3493 tlck->type =
3494 tlckXTREE | tlckTRUNCATE;
3495 }
3496 } else { /* COMMIT_WMAP */
3497
3498 /* free child extents covered by parent */
3499 xadlock.xdlist = &p->xad[index + 1];
3500 xadlock.count =
3501 le16_to_cpu(p->header.nextindex) -
3502 index - 1;
3503 txFreeMap(ip, (struct maplock *) & xadlock,
3504 NULL, COMMIT_WMAP);
3505 }
3506 BT_MARK_DIRTY(mp, ip);
3507
3508 p->header.nextindex = cpu_to_le16(index + 1);
3509 }
3510 XT_PUTPAGE(mp);
3511 goto getParent;
3512 }
3513
3514 /*
3515 * child page was empty:
3516 */
3517 nfreed += lengthXAD(&p->xad[index]);
3518
3519 /*
3520 * During working map update, child page's tlock must be handled
3521 * before parent's. This is because the parent's tlock will cause
3522 * the child's disk space to be marked available in the wmap, so
3523 * it's important that the child page be released by that time.
3524 *
3525 * ToDo: tlocks should be on doubly-linked list, so we can
3526 * quickly remove it and add it to the end.
3527 */
3528
3529 /*
3530 * Move parent page's tlock to the end of the tid's tlock list
3531 */
3532 if (log && mp->lid && (tblk->last != mp->lid) &&
3533 lid_to_tlock(mp->lid)->tid) {
3534 lid_t lid = mp->lid;
3535 struct tlock *prev;
3536
3537 tlck = lid_to_tlock(lid);
3538
3539 if (tblk->next == lid)
3540 tblk->next = tlck->next;
3541 else {
3542 for (prev = lid_to_tlock(tblk->next);
3543 prev->next != lid;
3544 prev = lid_to_tlock(prev->next)) {
3545 assert(prev->next);
3546 }
3547 prev->next = tlck->next;
3548 }
3549 lid_to_tlock(tblk->last)->next = lid;
3550 tlck->next = 0;
3551 tblk->last = lid;
3552 }
3553
3554 /*
3555 * parent page become empty: free the page
3556 */
3557 if (index == XTENTRYSTART) {
3558 if (log) { /* COMMIT_PWMAP */
3559 /* txCommit() with tlckFREE:
3560 * free child extents covered by parent;
3561 * invalidate parent if COMMIT_PWMAP;
3562 */
3563 tlck = txLock(tid, ip, mp, tlckXTREE);
3564 xtlck = (struct xtlock *) & tlck->lock;
3565 xtlck->hwm.offset =
3566 le16_to_cpu(p->header.nextindex) - 1;
3567 tlck->type = tlckXTREE | tlckFREE;
3568 } else { /* COMMIT_WMAP */
3569
3570 /* free child extents covered by parent */
3571 xadlock.xdlist = &p->xad[XTENTRYSTART];
3572 xadlock.count =
3573 le16_to_cpu(p->header.nextindex) -
3574 XTENTRYSTART;
3575 txFreeMap(ip, (struct maplock *) & xadlock, NULL,
3576 COMMIT_WMAP);
3577 }
3578 BT_MARK_DIRTY(mp, ip);
3579
3580 if (p->header.flag & BT_ROOT) {
3581 p->header.flag &= ~BT_INTERNAL;
3582 p->header.flag |= BT_LEAF;
3583 p->header.nextindex = cpu_to_le16(XTENTRYSTART);
3584 if (le16_to_cpu(p->header.maxentry) == XTROOTMAXSLOT) {
3585 /*
3586 * Shrink root down to allow inline
3587 * EA (otherwise fsck complains)
3588 */
3589 p->header.maxentry =
3590 cpu_to_le16(XTROOTINITSLOT);
3591 JFS_IP(ip)->mode2 |= INLINEEA;
3592 }
3593
3594 XT_PUTPAGE(mp); /* debug */
3595 goto out;
3596 } else {
3597 if (log) { /* COMMIT_PWMAP */
3598 /* page will be invalidated at tx completion
3599 */
3600 XT_PUTPAGE(mp);
3601 } else { /* COMMIT_WMAP */
3602
3603 if (mp->lid)
3604 lid_to_tlock(mp->lid)->flag |=
3605 tlckFREELOCK;
3606
3607 /* invalidate parent page */
3608 discard_metapage(mp);
3609 }
3610
3611 /* parent has become empty and freed:
3612 * go back up to its parent page
3613 */
3614 /* freed = 1; */
3615 goto getParent;
3616 }
3617 }
3618 /*
3619 * parent page still has entries for front region;
3620 */
3621 else {
3622 /* try truncate region covered by preceding entry
3623 * (process backward)
3624 */
3625 index--;
3626
3627 /* go back down to the child page corresponding
3628 * to the entry
3629 */
3630 goto getChild;
3631 }
3632
3633 /*
3634 * internal page: go down to child page of current entry
3635 */
3636 getChild:
3637 /* save current parent entry for the child page */
3638 if (BT_STACK_FULL(&btstack)) {
3639 jfs_error(ip->i_sb, "stack overrun!\n");
3640 XT_PUTPAGE(mp);
3641 return -EIO;
3642 }
3643 BT_PUSH(&btstack, bn, index);
3644
3645 /* get child page */
3646 xad = &p->xad[index];
3647 bn = addressXAD(xad);
3648
3649 /*
3650 * first access of each internal entry:
3651 */
3652 /* release parent page */
3653 XT_PUTPAGE(mp);
3654
3655 /* process the child page */
3656 goto getPage;
3657
3658 out:
3659 /*
3660 * update file resource stat
3661 */
3662 /* set size
3663 */
3664 if (S_ISDIR(ip->i_mode) && !newsize)
3665 ip->i_size = 1; /* fsck hates zero-length directories */
3666 else
3667 ip->i_size = newsize;
3668
3669 /* update quota allocation to reflect freed blocks */
3670 dquot_free_block(ip, nfreed);
3671
3672 /*
3673 * free tlock of invalidated pages
3674 */
3675 if (flag == COMMIT_WMAP)
3676 txFreelock(ip);
3677
3678 return newsize;
3679 }
3680
3681
3682 /*
3683 * xtTruncate_pmap()
3684 *
3685 * function:
3686 * Perform truncate to zero length for deleted file, leaving the
3687 * the xtree and working map untouched. This allows the file to
3688 * be accessed via open file handles, while the delete of the file
3689 * is committed to disk.
3690 *
3691 * parameter:
3692 * tid_t tid,
3693 * struct inode *ip,
3694 * s64 committed_size)
3695 *
3696 * return: new committed size
3697 *
3698 * note:
3699 *
3700 * To avoid deadlock by holding too many transaction locks, the
3701 * truncation may be broken up into multiple transactions.
3702 * The committed_size keeps track of part of the file has been
3703 * freed from the pmaps.
3704 */
3705 s64 xtTruncate_pmap(tid_t tid, struct inode *ip, s64 committed_size)
3706 {
3707 s64 bn;
3708 struct btstack btstack;
3709 int cmp;
3710 int index;
3711 int locked_leaves = 0;
3712 struct metapage *mp;
3713 xtpage_t *p;
3714 struct btframe *parent;
3715 int rc;
3716 struct tblock *tblk;
3717 struct tlock *tlck = NULL;
3718 xad_t *xad;
3719 int xlen;
3720 s64 xoff;
3721 struct xtlock *xtlck = NULL;
3722
3723 /* save object truncation type */
3724 tblk = tid_to_tblock(tid);
3725 tblk->xflag |= COMMIT_PMAP;
3726
3727 /* clear stack */
3728 BT_CLR(&btstack);
3729
3730 if (committed_size) {
3731 xoff = (committed_size >> JFS_SBI(ip->i_sb)->l2bsize) - 1;
3732 rc = xtSearch(ip, xoff, NULL, &cmp, &btstack, 0);
3733 if (rc)
3734 return rc;
3735
3736 XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
3737
3738 if (cmp != 0) {
3739 XT_PUTPAGE(mp);
3740 jfs_error(ip->i_sb, "did not find extent\n");
3741 return -EIO;
3742 }
3743 } else {
3744 /*
3745 * start with root
3746 *
3747 * root resides in the inode
3748 */
3749 bn = 0;
3750
3751 /*
3752 * first access of each page:
3753 */
3754 getPage:
3755 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3756 if (rc)
3757 return rc;
3758
3759 /* process entries backward from last index */
3760 index = le16_to_cpu(p->header.nextindex) - 1;
3761
3762 if (p->header.flag & BT_INTERNAL)
3763 goto getChild;
3764 }
3765
3766 /*
3767 * leaf page
3768 */
3769
3770 if (++locked_leaves > MAX_TRUNCATE_LEAVES) {
3771 /*
3772 * We need to limit the size of the transaction
3773 * to avoid exhausting pagecache & tlocks
3774 */
3775 xad = &p->xad[index];
3776 xoff = offsetXAD(xad);
3777 xlen = lengthXAD(xad);
3778 XT_PUTPAGE(mp);
3779 return (xoff + xlen) << JFS_SBI(ip->i_sb)->l2bsize;
3780 }
3781 tlck = txLock(tid, ip, mp, tlckXTREE);
3782 tlck->type = tlckXTREE | tlckFREE;
3783 xtlck = (struct xtlock *) & tlck->lock;
3784 xtlck->hwm.offset = index;
3785
3786
3787 XT_PUTPAGE(mp);
3788
3789 /*
3790 * go back up to the parent page
3791 */
3792 getParent:
3793 /* pop/restore parent entry for the current child page */
3794 if ((parent = BT_POP(&btstack)) == NULL)
3795 /* current page must have been root */
3796 goto out;
3797
3798 /* get back the parent page */
3799 bn = parent->bn;
3800 XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
3801 if (rc)
3802 return rc;
3803
3804 index = parent->index;
3805
3806 /*
3807 * parent page become empty: free the page
3808 */
3809 if (index == XTENTRYSTART) {
3810 /* txCommit() with tlckFREE:
3811 * free child extents covered by parent;
3812 * invalidate parent if COMMIT_PWMAP;
3813 */
3814 tlck = txLock(tid, ip, mp, tlckXTREE);
3815 xtlck = (struct xtlock *) & tlck->lock;
3816 xtlck->hwm.offset = le16_to_cpu(p->header.nextindex) - 1;
3817 tlck->type = tlckXTREE | tlckFREE;
3818
3819 XT_PUTPAGE(mp);
3820
3821 if (p->header.flag & BT_ROOT) {
3822
3823 goto out;
3824 } else {
3825 goto getParent;
3826 }
3827 }
3828 /*
3829 * parent page still has entries for front region;
3830 */
3831 else
3832 index--;
3833 /*
3834 * internal page: go down to child page of current entry
3835 */
3836 getChild:
3837 /* save current parent entry for the child page */
3838 if (BT_STACK_FULL(&btstack)) {
3839 jfs_error(ip->i_sb, "stack overrun!\n");
3840 XT_PUTPAGE(mp);
3841 return -EIO;
3842 }
3843 BT_PUSH(&btstack, bn, index);
3844
3845 /* get child page */
3846 xad = &p->xad[index];
3847 bn = addressXAD(xad);
3848
3849 /*
3850 * first access of each internal entry:
3851 */
3852 /* release parent page */
3853 XT_PUTPAGE(mp);
3854
3855 /* process the child page */
3856 goto getPage;
3857
3858 out:
3859
3860 return 0;
3861 }
3862
3863 #ifdef CONFIG_JFS_STATISTICS
3864 int jfs_xtstat_proc_show(struct seq_file *m, void *v)
3865 {
3866 seq_printf(m,
3867 "JFS Xtree statistics\n"
3868 "====================\n"
3869 "searches = %d\n"
3870 "fast searches = %d\n"
3871 "splits = %d\n",
3872 xtStat.search,
3873 xtStat.fastSearch,
3874 xtStat.split);
3875 return 0;
3876 }
3877 #endif