usb: add USB_QUIRK_RESET_RESUME for M-Audio 88es
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ubifs / tnc_commit.c
blob41920f357bbfc13e49668ef19fd6a0560ca195fc
1 /*
2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
23 /* This file implements TNC functions for committing */
25 #include "ubifs.h"
27 /**
28 * make_idx_node - make an index node for fill-the-gaps method of TNC commit.
29 * @c: UBIFS file-system description object
30 * @idx: buffer in which to place new index node
31 * @znode: znode from which to make new index node
32 * @lnum: LEB number where new index node will be written
33 * @offs: offset where new index node will be written
34 * @len: length of new index node
36 static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx,
37 struct ubifs_znode *znode, int lnum, int offs, int len)
39 struct ubifs_znode *zp;
40 int i, err;
42 /* Make index node */
43 idx->ch.node_type = UBIFS_IDX_NODE;
44 idx->child_cnt = cpu_to_le16(znode->child_cnt);
45 idx->level = cpu_to_le16(znode->level);
46 for (i = 0; i < znode->child_cnt; i++) {
47 struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
48 struct ubifs_zbranch *zbr = &znode->zbranch[i];
50 key_write_idx(c, &zbr->key, &br->key);
51 br->lnum = cpu_to_le32(zbr->lnum);
52 br->offs = cpu_to_le32(zbr->offs);
53 br->len = cpu_to_le32(zbr->len);
54 if (!zbr->lnum || !zbr->len) {
55 ubifs_err("bad ref in znode");
56 dbg_dump_znode(c, znode);
57 if (zbr->znode)
58 dbg_dump_znode(c, zbr->znode);
61 ubifs_prepare_node(c, idx, len, 0);
63 #ifdef CONFIG_UBIFS_FS_DEBUG
64 znode->lnum = lnum;
65 znode->offs = offs;
66 znode->len = len;
67 #endif
69 err = insert_old_idx_znode(c, znode);
71 /* Update the parent */
72 zp = znode->parent;
73 if (zp) {
74 struct ubifs_zbranch *zbr;
76 zbr = &zp->zbranch[znode->iip];
77 zbr->lnum = lnum;
78 zbr->offs = offs;
79 zbr->len = len;
80 } else {
81 c->zroot.lnum = lnum;
82 c->zroot.offs = offs;
83 c->zroot.len = len;
85 c->calc_idx_sz += ALIGN(len, 8);
87 atomic_long_dec(&c->dirty_zn_cnt);
89 ubifs_assert(ubifs_zn_dirty(znode));
90 ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
92 __clear_bit(DIRTY_ZNODE, &znode->flags);
93 __clear_bit(COW_ZNODE, &znode->flags);
95 return err;
98 /**
99 * fill_gap - make index nodes in gaps in dirty index LEBs.
100 * @c: UBIFS file-system description object
101 * @lnum: LEB number that gap appears in
102 * @gap_start: offset of start of gap
103 * @gap_end: offset of end of gap
104 * @dirt: adds dirty space to this
106 * This function returns the number of index nodes written into the gap.
108 static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end,
109 int *dirt)
111 int len, gap_remains, gap_pos, written, pad_len;
113 ubifs_assert((gap_start & 7) == 0);
114 ubifs_assert((gap_end & 7) == 0);
115 ubifs_assert(gap_end >= gap_start);
117 gap_remains = gap_end - gap_start;
118 if (!gap_remains)
119 return 0;
120 gap_pos = gap_start;
121 written = 0;
122 while (c->enext) {
123 len = ubifs_idx_node_sz(c, c->enext->child_cnt);
124 if (len < gap_remains) {
125 struct ubifs_znode *znode = c->enext;
126 const int alen = ALIGN(len, 8);
127 int err;
129 ubifs_assert(alen <= gap_remains);
130 err = make_idx_node(c, c->ileb_buf + gap_pos, znode,
131 lnum, gap_pos, len);
132 if (err)
133 return err;
134 gap_remains -= alen;
135 gap_pos += alen;
136 c->enext = znode->cnext;
137 if (c->enext == c->cnext)
138 c->enext = NULL;
139 written += 1;
140 } else
141 break;
143 if (gap_end == c->leb_size) {
144 c->ileb_len = ALIGN(gap_pos, c->min_io_size);
145 /* Pad to end of min_io_size */
146 pad_len = c->ileb_len - gap_pos;
147 } else
148 /* Pad to end of gap */
149 pad_len = gap_remains;
150 dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d",
151 lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len);
152 ubifs_pad(c, c->ileb_buf + gap_pos, pad_len);
153 *dirt += pad_len;
154 return written;
158 * find_old_idx - find an index node obsoleted since the last commit start.
159 * @c: UBIFS file-system description object
160 * @lnum: LEB number of obsoleted index node
161 * @offs: offset of obsoleted index node
163 * Returns %1 if found and %0 otherwise.
165 static int find_old_idx(struct ubifs_info *c, int lnum, int offs)
167 struct ubifs_old_idx *o;
168 struct rb_node *p;
170 p = c->old_idx.rb_node;
171 while (p) {
172 o = rb_entry(p, struct ubifs_old_idx, rb);
173 if (lnum < o->lnum)
174 p = p->rb_left;
175 else if (lnum > o->lnum)
176 p = p->rb_right;
177 else if (offs < o->offs)
178 p = p->rb_left;
179 else if (offs > o->offs)
180 p = p->rb_right;
181 else
182 return 1;
184 return 0;
188 * is_idx_node_in_use - determine if an index node can be overwritten.
189 * @c: UBIFS file-system description object
190 * @key: key of index node
191 * @level: index node level
192 * @lnum: LEB number of index node
193 * @offs: offset of index node
195 * If @key / @lnum / @offs identify an index node that was not part of the old
196 * index, then this function returns %0 (obsolete). Else if the index node was
197 * part of the old index but is now dirty %1 is returned, else if it is clean %2
198 * is returned. A negative error code is returned on failure.
200 static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key,
201 int level, int lnum, int offs)
203 int ret;
205 ret = is_idx_node_in_tnc(c, key, level, lnum, offs);
206 if (ret < 0)
207 return ret; /* Error code */
208 if (ret == 0)
209 if (find_old_idx(c, lnum, offs))
210 return 1;
211 return ret;
215 * layout_leb_in_gaps - layout index nodes using in-the-gaps method.
216 * @c: UBIFS file-system description object
217 * @p: return LEB number here
219 * This function lays out new index nodes for dirty znodes using in-the-gaps
220 * method of TNC commit.
221 * This function merely puts the next znode into the next gap, making no attempt
222 * to try to maximise the number of znodes that fit.
223 * This function returns the number of index nodes written into the gaps, or a
224 * negative error code on failure.
226 static int layout_leb_in_gaps(struct ubifs_info *c, int *p)
228 struct ubifs_scan_leb *sleb;
229 struct ubifs_scan_node *snod;
230 int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written;
232 tot_written = 0;
233 /* Get an index LEB with lots of obsolete index nodes */
234 lnum = ubifs_find_dirty_idx_leb(c);
235 if (lnum < 0)
237 * There also may be dirt in the index head that could be
238 * filled, however we do not check there at present.
240 return lnum; /* Error code */
241 *p = lnum;
242 dbg_gc("LEB %d", lnum);
244 * Scan the index LEB. We use the generic scan for this even though
245 * it is more comprehensive and less efficient than is needed for this
246 * purpose.
248 sleb = ubifs_scan(c, lnum, 0, c->ileb_buf, 0);
249 c->ileb_len = 0;
250 if (IS_ERR(sleb))
251 return PTR_ERR(sleb);
252 gap_start = 0;
253 list_for_each_entry(snod, &sleb->nodes, list) {
254 struct ubifs_idx_node *idx;
255 int in_use, level;
257 ubifs_assert(snod->type == UBIFS_IDX_NODE);
258 idx = snod->node;
259 key_read(c, ubifs_idx_key(c, idx), &snod->key);
260 level = le16_to_cpu(idx->level);
261 /* Determine if the index node is in use (not obsolete) */
262 in_use = is_idx_node_in_use(c, &snod->key, level, lnum,
263 snod->offs);
264 if (in_use < 0) {
265 ubifs_scan_destroy(sleb);
266 return in_use; /* Error code */
268 if (in_use) {
269 if (in_use == 1)
270 dirt += ALIGN(snod->len, 8);
272 * The obsolete index nodes form gaps that can be
273 * overwritten. This gap has ended because we have
274 * found an index node that is still in use
275 * i.e. not obsolete
277 gap_end = snod->offs;
278 /* Try to fill gap */
279 written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
280 if (written < 0) {
281 ubifs_scan_destroy(sleb);
282 return written; /* Error code */
284 tot_written += written;
285 gap_start = ALIGN(snod->offs + snod->len, 8);
288 ubifs_scan_destroy(sleb);
289 c->ileb_len = c->leb_size;
290 gap_end = c->leb_size;
291 /* Try to fill gap */
292 written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
293 if (written < 0)
294 return written; /* Error code */
295 tot_written += written;
296 if (tot_written == 0) {
297 struct ubifs_lprops lp;
299 dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
300 err = ubifs_read_one_lp(c, lnum, &lp);
301 if (err)
302 return err;
303 if (lp.free == c->leb_size) {
305 * We must have snatched this LEB from the idx_gc list
306 * so we need to correct the free and dirty space.
308 err = ubifs_change_one_lp(c, lnum,
309 c->leb_size - c->ileb_len,
310 dirt, 0, 0, 0);
311 if (err)
312 return err;
314 return 0;
316 err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt,
317 0, 0, 0);
318 if (err)
319 return err;
320 err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len,
321 UBI_SHORTTERM);
322 if (err)
323 return err;
324 dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
325 return tot_written;
329 * get_leb_cnt - calculate the number of empty LEBs needed to commit.
330 * @c: UBIFS file-system description object
331 * @cnt: number of znodes to commit
333 * This function returns the number of empty LEBs needed to commit @cnt znodes
334 * to the current index head. The number is not exact and may be more than
335 * needed.
337 static int get_leb_cnt(struct ubifs_info *c, int cnt)
339 int d;
341 /* Assume maximum index node size (i.e. overestimate space needed) */
342 cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz;
343 if (cnt < 0)
344 cnt = 0;
345 d = c->leb_size / c->max_idx_node_sz;
346 return DIV_ROUND_UP(cnt, d);
350 * layout_in_gaps - in-the-gaps method of committing TNC.
351 * @c: UBIFS file-system description object
352 * @cnt: number of dirty znodes to commit.
354 * This function lays out new index nodes for dirty znodes using in-the-gaps
355 * method of TNC commit.
357 * This function returns %0 on success and a negative error code on failure.
359 static int layout_in_gaps(struct ubifs_info *c, int cnt)
361 int err, leb_needed_cnt, written, *p;
363 dbg_gc("%d znodes to write", cnt);
365 c->gap_lebs = kmalloc(sizeof(int) * (c->lst.idx_lebs + 1), GFP_NOFS);
366 if (!c->gap_lebs)
367 return -ENOMEM;
369 p = c->gap_lebs;
370 do {
371 ubifs_assert(p < c->gap_lebs + sizeof(int) * c->lst.idx_lebs);
372 written = layout_leb_in_gaps(c, p);
373 if (written < 0) {
374 err = written;
375 if (err != -ENOSPC) {
376 kfree(c->gap_lebs);
377 c->gap_lebs = NULL;
378 return err;
380 if (dbg_force_in_the_gaps_enabled()) {
382 * Do not print scary warnings if the debugging
383 * option which forces in-the-gaps is enabled.
385 ubifs_warn("out of space");
386 dbg_dump_budg(c, &c->bi);
387 dbg_dump_lprops(c);
389 /* Try to commit anyway */
390 err = 0;
391 break;
393 p++;
394 cnt -= written;
395 leb_needed_cnt = get_leb_cnt(c, cnt);
396 dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt,
397 leb_needed_cnt, c->ileb_cnt);
398 } while (leb_needed_cnt > c->ileb_cnt);
400 *p = -1;
401 return 0;
405 * layout_in_empty_space - layout index nodes in empty space.
406 * @c: UBIFS file-system description object
408 * This function lays out new index nodes for dirty znodes using empty LEBs.
410 * This function returns %0 on success and a negative error code on failure.
412 static int layout_in_empty_space(struct ubifs_info *c)
414 struct ubifs_znode *znode, *cnext, *zp;
415 int lnum, offs, len, next_len, buf_len, buf_offs, used, avail;
416 int wlen, blen, err;
418 cnext = c->enext;
419 if (!cnext)
420 return 0;
422 lnum = c->ihead_lnum;
423 buf_offs = c->ihead_offs;
425 buf_len = ubifs_idx_node_sz(c, c->fanout);
426 buf_len = ALIGN(buf_len, c->min_io_size);
427 used = 0;
428 avail = buf_len;
430 /* Ensure there is enough room for first write */
431 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
432 if (buf_offs + next_len > c->leb_size)
433 lnum = -1;
435 while (1) {
436 znode = cnext;
438 len = ubifs_idx_node_sz(c, znode->child_cnt);
440 /* Determine the index node position */
441 if (lnum == -1) {
442 if (c->ileb_nxt >= c->ileb_cnt) {
443 ubifs_err("out of space");
444 return -ENOSPC;
446 lnum = c->ilebs[c->ileb_nxt++];
447 buf_offs = 0;
448 used = 0;
449 avail = buf_len;
452 offs = buf_offs + used;
454 #ifdef CONFIG_UBIFS_FS_DEBUG
455 znode->lnum = lnum;
456 znode->offs = offs;
457 znode->len = len;
458 #endif
460 /* Update the parent */
461 zp = znode->parent;
462 if (zp) {
463 struct ubifs_zbranch *zbr;
464 int i;
466 i = znode->iip;
467 zbr = &zp->zbranch[i];
468 zbr->lnum = lnum;
469 zbr->offs = offs;
470 zbr->len = len;
471 } else {
472 c->zroot.lnum = lnum;
473 c->zroot.offs = offs;
474 c->zroot.len = len;
476 c->calc_idx_sz += ALIGN(len, 8);
479 * Once lprops is updated, we can decrease the dirty znode count
480 * but it is easier to just do it here.
482 atomic_long_dec(&c->dirty_zn_cnt);
485 * Calculate the next index node length to see if there is
486 * enough room for it
488 cnext = znode->cnext;
489 if (cnext == c->cnext)
490 next_len = 0;
491 else
492 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
494 if (c->min_io_size == 1) {
495 buf_offs += ALIGN(len, 8);
496 if (next_len) {
497 if (buf_offs + next_len <= c->leb_size)
498 continue;
499 err = ubifs_update_one_lp(c, lnum, 0,
500 c->leb_size - buf_offs, 0, 0);
501 if (err)
502 return err;
503 lnum = -1;
504 continue;
506 err = ubifs_update_one_lp(c, lnum,
507 c->leb_size - buf_offs, 0, 0, 0);
508 if (err)
509 return err;
510 break;
513 /* Update buffer positions */
514 wlen = used + len;
515 used += ALIGN(len, 8);
516 avail -= ALIGN(len, 8);
518 if (next_len != 0 &&
519 buf_offs + used + next_len <= c->leb_size &&
520 avail > 0)
521 continue;
523 if (avail <= 0 && next_len &&
524 buf_offs + used + next_len <= c->leb_size)
525 blen = buf_len;
526 else
527 blen = ALIGN(wlen, c->min_io_size);
529 /* The buffer is full or there are no more znodes to do */
530 buf_offs += blen;
531 if (next_len) {
532 if (buf_offs + next_len > c->leb_size) {
533 err = ubifs_update_one_lp(c, lnum,
534 c->leb_size - buf_offs, blen - used,
535 0, 0);
536 if (err)
537 return err;
538 lnum = -1;
540 used -= blen;
541 if (used < 0)
542 used = 0;
543 avail = buf_len - used;
544 continue;
546 err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs,
547 blen - used, 0, 0);
548 if (err)
549 return err;
550 break;
553 #ifdef CONFIG_UBIFS_FS_DEBUG
554 c->dbg->new_ihead_lnum = lnum;
555 c->dbg->new_ihead_offs = buf_offs;
556 #endif
558 return 0;
562 * layout_commit - determine positions of index nodes to commit.
563 * @c: UBIFS file-system description object
564 * @no_space: indicates that insufficient empty LEBs were allocated
565 * @cnt: number of znodes to commit
567 * Calculate and update the positions of index nodes to commit. If there were
568 * an insufficient number of empty LEBs allocated, then index nodes are placed
569 * into the gaps created by obsolete index nodes in non-empty index LEBs. For
570 * this purpose, an obsolete index node is one that was not in the index as at
571 * the end of the last commit. To write "in-the-gaps" requires that those index
572 * LEBs are updated atomically in-place.
574 static int layout_commit(struct ubifs_info *c, int no_space, int cnt)
576 int err;
578 if (no_space) {
579 err = layout_in_gaps(c, cnt);
580 if (err)
581 return err;
583 err = layout_in_empty_space(c);
584 return err;
588 * find_first_dirty - find first dirty znode.
589 * @znode: znode to begin searching from
591 static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode)
593 int i, cont;
595 if (!znode)
596 return NULL;
598 while (1) {
599 if (znode->level == 0) {
600 if (ubifs_zn_dirty(znode))
601 return znode;
602 return NULL;
604 cont = 0;
605 for (i = 0; i < znode->child_cnt; i++) {
606 struct ubifs_zbranch *zbr = &znode->zbranch[i];
608 if (zbr->znode && ubifs_zn_dirty(zbr->znode)) {
609 znode = zbr->znode;
610 cont = 1;
611 break;
614 if (!cont) {
615 if (ubifs_zn_dirty(znode))
616 return znode;
617 return NULL;
623 * find_next_dirty - find next dirty znode.
624 * @znode: znode to begin searching from
626 static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode)
628 int n = znode->iip + 1;
630 znode = znode->parent;
631 if (!znode)
632 return NULL;
633 for (; n < znode->child_cnt; n++) {
634 struct ubifs_zbranch *zbr = &znode->zbranch[n];
636 if (zbr->znode && ubifs_zn_dirty(zbr->znode))
637 return find_first_dirty(zbr->znode);
639 return znode;
643 * get_znodes_to_commit - create list of dirty znodes to commit.
644 * @c: UBIFS file-system description object
646 * This function returns the number of znodes to commit.
648 static int get_znodes_to_commit(struct ubifs_info *c)
650 struct ubifs_znode *znode, *cnext;
651 int cnt = 0;
653 c->cnext = find_first_dirty(c->zroot.znode);
654 znode = c->enext = c->cnext;
655 if (!znode) {
656 dbg_cmt("no znodes to commit");
657 return 0;
659 cnt += 1;
660 while (1) {
661 ubifs_assert(!test_bit(COW_ZNODE, &znode->flags));
662 __set_bit(COW_ZNODE, &znode->flags);
663 znode->alt = 0;
664 cnext = find_next_dirty(znode);
665 if (!cnext) {
666 znode->cnext = c->cnext;
667 break;
669 znode->cnext = cnext;
670 znode = cnext;
671 cnt += 1;
673 dbg_cmt("committing %d znodes", cnt);
674 ubifs_assert(cnt == atomic_long_read(&c->dirty_zn_cnt));
675 return cnt;
679 * alloc_idx_lebs - allocate empty LEBs to be used to commit.
680 * @c: UBIFS file-system description object
681 * @cnt: number of znodes to commit
683 * This function returns %-ENOSPC if it cannot allocate a sufficient number of
684 * empty LEBs. %0 is returned on success, otherwise a negative error code
685 * is returned.
687 static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
689 int i, leb_cnt, lnum;
691 c->ileb_cnt = 0;
692 c->ileb_nxt = 0;
693 leb_cnt = get_leb_cnt(c, cnt);
694 dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt);
695 if (!leb_cnt)
696 return 0;
697 c->ilebs = kmalloc(leb_cnt * sizeof(int), GFP_NOFS);
698 if (!c->ilebs)
699 return -ENOMEM;
700 for (i = 0; i < leb_cnt; i++) {
701 lnum = ubifs_find_free_leb_for_idx(c);
702 if (lnum < 0)
703 return lnum;
704 c->ilebs[c->ileb_cnt++] = lnum;
705 dbg_cmt("LEB %d", lnum);
707 if (dbg_force_in_the_gaps())
708 return -ENOSPC;
709 return 0;
713 * free_unused_idx_lebs - free unused LEBs that were allocated for the commit.
714 * @c: UBIFS file-system description object
716 * It is possible that we allocate more empty LEBs for the commit than we need.
717 * This functions frees the surplus.
719 * This function returns %0 on success and a negative error code on failure.
721 static int free_unused_idx_lebs(struct ubifs_info *c)
723 int i, err = 0, lnum, er;
725 for (i = c->ileb_nxt; i < c->ileb_cnt; i++) {
726 lnum = c->ilebs[i];
727 dbg_cmt("LEB %d", lnum);
728 er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
729 LPROPS_INDEX | LPROPS_TAKEN, 0);
730 if (!err)
731 err = er;
733 return err;
737 * free_idx_lebs - free unused LEBs after commit end.
738 * @c: UBIFS file-system description object
740 * This function returns %0 on success and a negative error code on failure.
742 static int free_idx_lebs(struct ubifs_info *c)
744 int err;
746 err = free_unused_idx_lebs(c);
747 kfree(c->ilebs);
748 c->ilebs = NULL;
749 return err;
753 * ubifs_tnc_start_commit - start TNC commit.
754 * @c: UBIFS file-system description object
755 * @zroot: new index root position is returned here
757 * This function prepares the list of indexing nodes to commit and lays out
758 * their positions on flash. If there is not enough free space it uses the
759 * in-gap commit method. Returns zero in case of success and a negative error
760 * code in case of failure.
762 int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot)
764 int err = 0, cnt;
766 mutex_lock(&c->tnc_mutex);
767 err = dbg_check_tnc(c, 1);
768 if (err)
769 goto out;
770 cnt = get_znodes_to_commit(c);
771 if (cnt != 0) {
772 int no_space = 0;
774 err = alloc_idx_lebs(c, cnt);
775 if (err == -ENOSPC)
776 no_space = 1;
777 else if (err)
778 goto out_free;
779 err = layout_commit(c, no_space, cnt);
780 if (err)
781 goto out_free;
782 ubifs_assert(atomic_long_read(&c->dirty_zn_cnt) == 0);
783 err = free_unused_idx_lebs(c);
784 if (err)
785 goto out;
787 destroy_old_idx(c);
788 memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch));
790 err = ubifs_save_dirty_idx_lnums(c);
791 if (err)
792 goto out;
794 spin_lock(&c->space_lock);
796 * Although we have not finished committing yet, update size of the
797 * committed index ('c->bi.old_idx_sz') and zero out the index growth
798 * budget. It is OK to do this now, because we've reserved all the
799 * space which is needed to commit the index, and it is save for the
800 * budgeting subsystem to assume the index is already committed,
801 * even though it is not.
803 ubifs_assert(c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c));
804 c->bi.old_idx_sz = c->calc_idx_sz;
805 c->bi.uncommitted_idx = 0;
806 c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
807 spin_unlock(&c->space_lock);
808 mutex_unlock(&c->tnc_mutex);
810 dbg_cmt("number of index LEBs %d", c->lst.idx_lebs);
811 dbg_cmt("size of index %llu", c->calc_idx_sz);
812 return err;
814 out_free:
815 free_idx_lebs(c);
816 out:
817 mutex_unlock(&c->tnc_mutex);
818 return err;
822 * write_index - write index nodes.
823 * @c: UBIFS file-system description object
825 * This function writes the index nodes whose positions were laid out in the
826 * layout_in_empty_space function.
828 static int write_index(struct ubifs_info *c)
830 struct ubifs_idx_node *idx;
831 struct ubifs_znode *znode, *cnext;
832 int i, lnum, offs, len, next_len, buf_len, buf_offs, used;
833 int avail, wlen, err, lnum_pos = 0;
835 cnext = c->enext;
836 if (!cnext)
837 return 0;
840 * Always write index nodes to the index head so that index nodes and
841 * other types of nodes are never mixed in the same erase block.
843 lnum = c->ihead_lnum;
844 buf_offs = c->ihead_offs;
846 /* Allocate commit buffer */
847 buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size);
848 used = 0;
849 avail = buf_len;
851 /* Ensure there is enough room for first write */
852 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
853 if (buf_offs + next_len > c->leb_size) {
854 err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0,
855 LPROPS_TAKEN);
856 if (err)
857 return err;
858 lnum = -1;
861 while (1) {
862 cond_resched();
864 znode = cnext;
865 idx = c->cbuf + used;
867 /* Make index node */
868 idx->ch.node_type = UBIFS_IDX_NODE;
869 idx->child_cnt = cpu_to_le16(znode->child_cnt);
870 idx->level = cpu_to_le16(znode->level);
871 for (i = 0; i < znode->child_cnt; i++) {
872 struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
873 struct ubifs_zbranch *zbr = &znode->zbranch[i];
875 key_write_idx(c, &zbr->key, &br->key);
876 br->lnum = cpu_to_le32(zbr->lnum);
877 br->offs = cpu_to_le32(zbr->offs);
878 br->len = cpu_to_le32(zbr->len);
879 if (!zbr->lnum || !zbr->len) {
880 ubifs_err("bad ref in znode");
881 dbg_dump_znode(c, znode);
882 if (zbr->znode)
883 dbg_dump_znode(c, zbr->znode);
886 len = ubifs_idx_node_sz(c, znode->child_cnt);
887 ubifs_prepare_node(c, idx, len, 0);
889 /* Determine the index node position */
890 if (lnum == -1) {
891 lnum = c->ilebs[lnum_pos++];
892 buf_offs = 0;
893 used = 0;
894 avail = buf_len;
896 offs = buf_offs + used;
898 #ifdef CONFIG_UBIFS_FS_DEBUG
899 if (lnum != znode->lnum || offs != znode->offs ||
900 len != znode->len) {
901 ubifs_err("inconsistent znode posn");
902 return -EINVAL;
904 #endif
906 /* Grab some stuff from znode while we still can */
907 cnext = znode->cnext;
909 ubifs_assert(ubifs_zn_dirty(znode));
910 ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
913 * It is important that other threads should see %DIRTY_ZNODE
914 * flag cleared before %COW_ZNODE. Specifically, it matters in
915 * the 'dirty_cow_znode()' function. This is the reason for the
916 * first barrier. Also, we want the bit changes to be seen to
917 * other threads ASAP, to avoid unnecesarry copying, which is
918 * the reason for the second barrier.
920 clear_bit(DIRTY_ZNODE, &znode->flags);
921 smp_mb__before_clear_bit();
922 clear_bit(COW_ZNODE, &znode->flags);
923 smp_mb__after_clear_bit();
925 /* Do not access znode from this point on */
927 /* Update buffer positions */
928 wlen = used + len;
929 used += ALIGN(len, 8);
930 avail -= ALIGN(len, 8);
933 * Calculate the next index node length to see if there is
934 * enough room for it
936 if (cnext == c->cnext)
937 next_len = 0;
938 else
939 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
941 if (c->min_io_size == 1) {
943 * Write the prepared index node immediately if there is
944 * no minimum IO size
946 err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs,
947 wlen, UBI_SHORTTERM);
948 if (err)
949 return err;
950 buf_offs += ALIGN(wlen, 8);
951 if (next_len) {
952 used = 0;
953 avail = buf_len;
954 if (buf_offs + next_len > c->leb_size) {
955 err = ubifs_update_one_lp(c, lnum,
956 LPROPS_NC, 0, 0, LPROPS_TAKEN);
957 if (err)
958 return err;
959 lnum = -1;
961 continue;
963 } else {
964 int blen, nxt_offs = buf_offs + used + next_len;
966 if (next_len && nxt_offs <= c->leb_size) {
967 if (avail > 0)
968 continue;
969 else
970 blen = buf_len;
971 } else {
972 wlen = ALIGN(wlen, 8);
973 blen = ALIGN(wlen, c->min_io_size);
974 ubifs_pad(c, c->cbuf + wlen, blen - wlen);
977 * The buffer is full or there are no more znodes
978 * to do
980 err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs,
981 blen, UBI_SHORTTERM);
982 if (err)
983 return err;
984 buf_offs += blen;
985 if (next_len) {
986 if (nxt_offs > c->leb_size) {
987 err = ubifs_update_one_lp(c, lnum,
988 LPROPS_NC, 0, 0, LPROPS_TAKEN);
989 if (err)
990 return err;
991 lnum = -1;
993 used -= blen;
994 if (used < 0)
995 used = 0;
996 avail = buf_len - used;
997 memmove(c->cbuf, c->cbuf + blen, used);
998 continue;
1001 break;
1004 #ifdef CONFIG_UBIFS_FS_DEBUG
1005 if (lnum != c->dbg->new_ihead_lnum ||
1006 buf_offs != c->dbg->new_ihead_offs) {
1007 ubifs_err("inconsistent ihead");
1008 return -EINVAL;
1010 #endif
1012 c->ihead_lnum = lnum;
1013 c->ihead_offs = buf_offs;
1015 return 0;
1019 * free_obsolete_znodes - free obsolete znodes.
1020 * @c: UBIFS file-system description object
1022 * At the end of commit end, obsolete znodes are freed.
1024 static void free_obsolete_znodes(struct ubifs_info *c)
1026 struct ubifs_znode *znode, *cnext;
1028 cnext = c->cnext;
1029 do {
1030 znode = cnext;
1031 cnext = znode->cnext;
1032 if (test_bit(OBSOLETE_ZNODE, &znode->flags))
1033 kfree(znode);
1034 else {
1035 znode->cnext = NULL;
1036 atomic_long_inc(&c->clean_zn_cnt);
1037 atomic_long_inc(&ubifs_clean_zn_cnt);
1039 } while (cnext != c->cnext);
1043 * return_gap_lebs - return LEBs used by the in-gap commit method.
1044 * @c: UBIFS file-system description object
1046 * This function clears the "taken" flag for the LEBs which were used by the
1047 * "commit in-the-gaps" method.
1049 static int return_gap_lebs(struct ubifs_info *c)
1051 int *p, err;
1053 if (!c->gap_lebs)
1054 return 0;
1056 dbg_cmt("");
1057 for (p = c->gap_lebs; *p != -1; p++) {
1058 err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0,
1059 LPROPS_TAKEN, 0);
1060 if (err)
1061 return err;
1064 kfree(c->gap_lebs);
1065 c->gap_lebs = NULL;
1066 return 0;
1070 * ubifs_tnc_end_commit - update the TNC for commit end.
1071 * @c: UBIFS file-system description object
1073 * Write the dirty znodes.
1075 int ubifs_tnc_end_commit(struct ubifs_info *c)
1077 int err;
1079 if (!c->cnext)
1080 return 0;
1082 err = return_gap_lebs(c);
1083 if (err)
1084 return err;
1086 err = write_index(c);
1087 if (err)
1088 return err;
1090 mutex_lock(&c->tnc_mutex);
1092 dbg_cmt("TNC height is %d", c->zroot.znode->level + 1);
1094 free_obsolete_znodes(c);
1096 c->cnext = NULL;
1097 kfree(c->ilebs);
1098 c->ilebs = NULL;
1100 mutex_unlock(&c->tnc_mutex);
1102 return 0;