1 // SPDX-License-Identifier: GPL-2.0-only
3 * This file is part of UBIFS.
5 * Copyright (C) 2006-2008 Nokia Corporation.
7 * Authors: Adrian Hunter
8 * Artem Bityutskiy (Битюцкий Артём)
11 /* This file implements TNC functions for committing */
13 #include <linux/random.h>
17 * make_idx_node - make an index node for fill-the-gaps method of TNC commit.
18 * @c: UBIFS file-system description object
19 * @idx: buffer in which to place new index node
20 * @znode: znode from which to make new index node
21 * @lnum: LEB number where new index node will be written
22 * @offs: offset where new index node will be written
23 * @len: length of new index node
25 static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx,
26 struct ubifs_znode *znode, int lnum, int offs, int len)
28 struct ubifs_znode *zp;
29 u8 hash[UBIFS_HASH_ARR_SZ];
33 idx->ch.node_type = UBIFS_IDX_NODE;
34 idx->child_cnt = cpu_to_le16(znode->child_cnt);
35 idx->level = cpu_to_le16(znode->level);
36 for (i = 0; i < znode->child_cnt; i++) {
37 struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
38 struct ubifs_zbranch *zbr = &znode->zbranch[i];
40 key_write_idx(c, &zbr->key, &br->key);
41 br->lnum = cpu_to_le32(zbr->lnum);
42 br->offs = cpu_to_le32(zbr->offs);
43 br->len = cpu_to_le32(zbr->len);
44 ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br));
45 if (!zbr->lnum || !zbr->len) {
46 ubifs_err(c, "bad ref in znode");
47 ubifs_dump_znode(c, znode);
49 ubifs_dump_znode(c, zbr->znode);
54 ubifs_prepare_node(c, idx, len, 0);
55 ubifs_node_calc_hash(c, idx, hash);
61 err = insert_old_idx_znode(c, znode);
63 /* Update the parent */
66 struct ubifs_zbranch *zbr;
68 zbr = &zp->zbranch[znode->iip];
72 ubifs_copy_hash(c, hash, zbr->hash);
77 ubifs_copy_hash(c, hash, c->zroot.hash);
79 c->calc_idx_sz += ALIGN(len, 8);
81 atomic_long_dec(&c->dirty_zn_cnt);
83 ubifs_assert(c, ubifs_zn_dirty(znode));
84 ubifs_assert(c, ubifs_zn_cow(znode));
87 * Note, unlike 'write_index()' we do not add memory barriers here
88 * because this function is called with @c->tnc_mutex locked.
90 __clear_bit(DIRTY_ZNODE, &znode->flags);
91 __clear_bit(COW_ZNODE, &znode->flags);
97 * fill_gap - make index nodes in gaps in dirty index LEBs.
98 * @c: UBIFS file-system description object
99 * @lnum: LEB number that gap appears in
100 * @gap_start: offset of start of gap
101 * @gap_end: offset of end of gap
102 * @dirt: adds dirty space to this
104 * This function returns the number of index nodes written into the gap.
106 static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end,
109 int len, gap_remains, gap_pos, written, pad_len;
111 ubifs_assert(c, (gap_start & 7) == 0);
112 ubifs_assert(c, (gap_end & 7) == 0);
113 ubifs_assert(c, gap_end >= gap_start);
115 gap_remains = gap_end - gap_start;
121 len = ubifs_idx_node_sz(c, c->enext->child_cnt);
122 if (len < gap_remains) {
123 struct ubifs_znode *znode = c->enext;
124 const int alen = ALIGN(len, 8);
127 ubifs_assert(c, alen <= gap_remains);
128 err = make_idx_node(c, c->ileb_buf + gap_pos, znode,
134 c->enext = znode->cnext;
135 if (c->enext == c->cnext)
141 if (gap_end == c->leb_size) {
142 c->ileb_len = ALIGN(gap_pos, c->min_io_size);
143 /* Pad to end of min_io_size */
144 pad_len = c->ileb_len - gap_pos;
146 /* Pad to end of gap */
147 pad_len = gap_remains;
148 dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d",
149 lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len);
150 ubifs_pad(c, c->ileb_buf + gap_pos, pad_len);
156 * find_old_idx - find an index node obsoleted since the last commit start.
157 * @c: UBIFS file-system description object
158 * @lnum: LEB number of obsoleted index node
159 * @offs: offset of obsoleted index node
161 * Returns %1 if found and %0 otherwise.
163 static int find_old_idx(struct ubifs_info *c, int lnum, int offs)
165 struct ubifs_old_idx *o;
168 p = c->old_idx.rb_node;
170 o = rb_entry(p, struct ubifs_old_idx, rb);
173 else if (lnum > o->lnum)
175 else if (offs < o->offs)
177 else if (offs > o->offs)
186 * is_idx_node_in_use - determine if an index node can be overwritten.
187 * @c: UBIFS file-system description object
188 * @key: key of index node
189 * @level: index node level
190 * @lnum: LEB number of index node
191 * @offs: offset of index node
193 * If @key / @lnum / @offs identify an index node that was not part of the old
194 * index, then this function returns %0 (obsolete). Else if the index node was
195 * part of the old index but is now dirty %1 is returned, else if it is clean %2
196 * is returned. A negative error code is returned on failure.
198 static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key,
199 int level, int lnum, int offs)
203 ret = is_idx_node_in_tnc(c, key, level, lnum, offs);
205 return ret; /* Error code */
207 if (find_old_idx(c, lnum, offs))
213 * layout_leb_in_gaps - layout index nodes using in-the-gaps method.
214 * @c: UBIFS file-system description object
215 * @p: return LEB number here
217 * This function lays out new index nodes for dirty znodes using in-the-gaps
218 * method of TNC commit.
219 * This function merely puts the next znode into the next gap, making no attempt
220 * to try to maximise the number of znodes that fit.
221 * This function returns the number of index nodes written into the gaps, or a
222 * negative error code on failure.
224 static int layout_leb_in_gaps(struct ubifs_info *c, int *p)
226 struct ubifs_scan_leb *sleb;
227 struct ubifs_scan_node *snod;
228 int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written;
231 /* Get an index LEB with lots of obsolete index nodes */
232 lnum = ubifs_find_dirty_idx_leb(c);
235 * There also may be dirt in the index head that could be
236 * filled, however we do not check there at present.
238 return lnum; /* Error code */
240 dbg_gc("LEB %d", lnum);
242 * Scan the index LEB. We use the generic scan for this even though
243 * it is more comprehensive and less efficient than is needed for this
246 sleb = ubifs_scan(c, lnum, 0, c->ileb_buf, 0);
249 return PTR_ERR(sleb);
251 list_for_each_entry(snod, &sleb->nodes, list) {
252 struct ubifs_idx_node *idx;
255 ubifs_assert(c, snod->type == UBIFS_IDX_NODE);
257 key_read(c, ubifs_idx_key(c, idx), &snod->key);
258 level = le16_to_cpu(idx->level);
259 /* Determine if the index node is in use (not obsolete) */
260 in_use = is_idx_node_in_use(c, &snod->key, level, lnum,
263 ubifs_scan_destroy(sleb);
264 return in_use; /* Error code */
268 dirt += ALIGN(snod->len, 8);
270 * The obsolete index nodes form gaps that can be
271 * overwritten. This gap has ended because we have
272 * found an index node that is still in use
275 gap_end = snod->offs;
276 /* Try to fill gap */
277 written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
279 ubifs_scan_destroy(sleb);
280 return written; /* Error code */
282 tot_written += written;
283 gap_start = ALIGN(snod->offs + snod->len, 8);
286 ubifs_scan_destroy(sleb);
287 c->ileb_len = c->leb_size;
288 gap_end = c->leb_size;
289 /* Try to fill gap */
290 written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
292 return written; /* Error code */
293 tot_written += written;
294 if (tot_written == 0) {
295 struct ubifs_lprops lp;
297 dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
298 err = ubifs_read_one_lp(c, lnum, &lp);
301 if (lp.free == c->leb_size) {
303 * We must have snatched this LEB from the idx_gc list
304 * so we need to correct the free and dirty space.
306 err = ubifs_change_one_lp(c, lnum,
307 c->leb_size - c->ileb_len,
314 err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt,
318 err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len);
321 dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
326 * get_leb_cnt - calculate the number of empty LEBs needed to commit.
327 * @c: UBIFS file-system description object
328 * @cnt: number of znodes to commit
330 * This function returns the number of empty LEBs needed to commit @cnt znodes
331 * to the current index head. The number is not exact and may be more than
334 static int get_leb_cnt(struct ubifs_info *c, int cnt)
338 /* Assume maximum index node size (i.e. overestimate space needed) */
339 cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz;
342 d = c->leb_size / c->max_idx_node_sz;
343 return DIV_ROUND_UP(cnt, d);
347 * layout_in_gaps - in-the-gaps method of committing TNC.
348 * @c: UBIFS file-system description object
349 * @cnt: number of dirty znodes to commit.
351 * This function lays out new index nodes for dirty znodes using in-the-gaps
352 * method of TNC commit.
354 * This function returns %0 on success and a negative error code on failure.
356 static int layout_in_gaps(struct ubifs_info *c, int cnt)
358 int err, leb_needed_cnt, written, *p;
360 dbg_gc("%d znodes to write", cnt);
362 c->gap_lebs = kmalloc_array(c->lst.idx_lebs + 1, sizeof(int),
369 ubifs_assert(c, p < c->gap_lebs + c->lst.idx_lebs);
370 written = layout_leb_in_gaps(c, p);
373 if (err != -ENOSPC) {
378 if (!dbg_is_chk_index(c)) {
380 * Do not print scary warnings if the debugging
381 * option which forces in-the-gaps is enabled.
383 ubifs_warn(c, "out of space");
384 ubifs_dump_budg(c, &c->bi);
385 ubifs_dump_lprops(c);
387 /* Try to commit anyway */
392 leb_needed_cnt = get_leb_cnt(c, cnt);
393 dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt,
394 leb_needed_cnt, c->ileb_cnt);
395 } while (leb_needed_cnt > c->ileb_cnt);
402 * layout_in_empty_space - layout index nodes in empty space.
403 * @c: UBIFS file-system description object
405 * This function lays out new index nodes for dirty znodes using empty LEBs.
407 * This function returns %0 on success and a negative error code on failure.
409 static int layout_in_empty_space(struct ubifs_info *c)
411 struct ubifs_znode *znode, *cnext, *zp;
412 int lnum, offs, len, next_len, buf_len, buf_offs, used, avail;
419 lnum = c->ihead_lnum;
420 buf_offs = c->ihead_offs;
422 buf_len = ubifs_idx_node_sz(c, c->fanout);
423 buf_len = ALIGN(buf_len, c->min_io_size);
427 /* Ensure there is enough room for first write */
428 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
429 if (buf_offs + next_len > c->leb_size)
435 len = ubifs_idx_node_sz(c, znode->child_cnt);
437 /* Determine the index node position */
439 if (c->ileb_nxt >= c->ileb_cnt) {
440 ubifs_err(c, "out of space");
443 lnum = c->ilebs[c->ileb_nxt++];
449 offs = buf_offs + used;
455 /* Update the parent */
458 struct ubifs_zbranch *zbr;
462 zbr = &zp->zbranch[i];
467 c->zroot.lnum = lnum;
468 c->zroot.offs = offs;
471 c->calc_idx_sz += ALIGN(len, 8);
474 * Once lprops is updated, we can decrease the dirty znode count
475 * but it is easier to just do it here.
477 atomic_long_dec(&c->dirty_zn_cnt);
480 * Calculate the next index node length to see if there is
483 cnext = znode->cnext;
484 if (cnext == c->cnext)
487 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
489 /* Update buffer positions */
491 used += ALIGN(len, 8);
492 avail -= ALIGN(len, 8);
495 buf_offs + used + next_len <= c->leb_size &&
499 if (avail <= 0 && next_len &&
500 buf_offs + used + next_len <= c->leb_size)
503 blen = ALIGN(wlen, c->min_io_size);
505 /* The buffer is full or there are no more znodes to do */
508 if (buf_offs + next_len > c->leb_size) {
509 err = ubifs_update_one_lp(c, lnum,
510 c->leb_size - buf_offs, blen - used,
519 avail = buf_len - used;
522 err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs,
529 c->dbg->new_ihead_lnum = lnum;
530 c->dbg->new_ihead_offs = buf_offs;
536 * layout_commit - determine positions of index nodes to commit.
537 * @c: UBIFS file-system description object
538 * @no_space: indicates that insufficient empty LEBs were allocated
539 * @cnt: number of znodes to commit
541 * Calculate and update the positions of index nodes to commit. If there were
542 * an insufficient number of empty LEBs allocated, then index nodes are placed
543 * into the gaps created by obsolete index nodes in non-empty index LEBs. For
544 * this purpose, an obsolete index node is one that was not in the index as at
545 * the end of the last commit. To write "in-the-gaps" requires that those index
546 * LEBs are updated atomically in-place.
548 static int layout_commit(struct ubifs_info *c, int no_space, int cnt)
553 err = layout_in_gaps(c, cnt);
557 err = layout_in_empty_space(c);
562 * find_first_dirty - find first dirty znode.
563 * @znode: znode to begin searching from
565 static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode)
573 if (znode->level == 0) {
574 if (ubifs_zn_dirty(znode))
579 for (i = 0; i < znode->child_cnt; i++) {
580 struct ubifs_zbranch *zbr = &znode->zbranch[i];
582 if (zbr->znode && ubifs_zn_dirty(zbr->znode)) {
589 if (ubifs_zn_dirty(znode))
597 * find_next_dirty - find next dirty znode.
598 * @znode: znode to begin searching from
600 static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode)
602 int n = znode->iip + 1;
604 znode = znode->parent;
607 for (; n < znode->child_cnt; n++) {
608 struct ubifs_zbranch *zbr = &znode->zbranch[n];
610 if (zbr->znode && ubifs_zn_dirty(zbr->znode))
611 return find_first_dirty(zbr->znode);
617 * get_znodes_to_commit - create list of dirty znodes to commit.
618 * @c: UBIFS file-system description object
620 * This function returns the number of znodes to commit.
622 static int get_znodes_to_commit(struct ubifs_info *c)
624 struct ubifs_znode *znode, *cnext;
627 c->cnext = find_first_dirty(c->zroot.znode);
628 znode = c->enext = c->cnext;
630 dbg_cmt("no znodes to commit");
635 ubifs_assert(c, !ubifs_zn_cow(znode));
636 __set_bit(COW_ZNODE, &znode->flags);
638 cnext = find_next_dirty(znode);
640 znode->cnext = c->cnext;
643 znode->cparent = znode->parent;
644 znode->ciip = znode->iip;
645 znode->cnext = cnext;
649 dbg_cmt("committing %d znodes", cnt);
650 ubifs_assert(c, cnt == atomic_long_read(&c->dirty_zn_cnt));
655 * alloc_idx_lebs - allocate empty LEBs to be used to commit.
656 * @c: UBIFS file-system description object
657 * @cnt: number of znodes to commit
659 * This function returns %-ENOSPC if it cannot allocate a sufficient number of
660 * empty LEBs. %0 is returned on success, otherwise a negative error code
663 static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
665 int i, leb_cnt, lnum;
669 leb_cnt = get_leb_cnt(c, cnt);
670 dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt);
673 c->ilebs = kmalloc_array(leb_cnt, sizeof(int), GFP_NOFS);
676 for (i = 0; i < leb_cnt; i++) {
677 lnum = ubifs_find_free_leb_for_idx(c);
680 c->ilebs[c->ileb_cnt++] = lnum;
681 dbg_cmt("LEB %d", lnum);
683 if (dbg_is_chk_index(c) && !(prandom_u32() & 7))
689 * free_unused_idx_lebs - free unused LEBs that were allocated for the commit.
690 * @c: UBIFS file-system description object
692 * It is possible that we allocate more empty LEBs for the commit than we need.
693 * This functions frees the surplus.
695 * This function returns %0 on success and a negative error code on failure.
697 static int free_unused_idx_lebs(struct ubifs_info *c)
699 int i, err = 0, lnum, er;
701 for (i = c->ileb_nxt; i < c->ileb_cnt; i++) {
703 dbg_cmt("LEB %d", lnum);
704 er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
705 LPROPS_INDEX | LPROPS_TAKEN, 0);
713 * free_idx_lebs - free unused LEBs after commit end.
714 * @c: UBIFS file-system description object
716 * This function returns %0 on success and a negative error code on failure.
718 static int free_idx_lebs(struct ubifs_info *c)
722 err = free_unused_idx_lebs(c);
729 * ubifs_tnc_start_commit - start TNC commit.
730 * @c: UBIFS file-system description object
731 * @zroot: new index root position is returned here
733 * This function prepares the list of indexing nodes to commit and lays out
734 * their positions on flash. If there is not enough free space it uses the
735 * in-gap commit method. Returns zero in case of success and a negative error
736 * code in case of failure.
738 int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot)
742 mutex_lock(&c->tnc_mutex);
743 err = dbg_check_tnc(c, 1);
746 cnt = get_znodes_to_commit(c);
750 err = alloc_idx_lebs(c, cnt);
755 err = layout_commit(c, no_space, cnt);
758 ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0);
759 err = free_unused_idx_lebs(c);
764 memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch));
766 err = ubifs_save_dirty_idx_lnums(c);
770 spin_lock(&c->space_lock);
772 * Although we have not finished committing yet, update size of the
773 * committed index ('c->bi.old_idx_sz') and zero out the index growth
774 * budget. It is OK to do this now, because we've reserved all the
775 * space which is needed to commit the index, and it is save for the
776 * budgeting subsystem to assume the index is already committed,
777 * even though it is not.
779 ubifs_assert(c, c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c));
780 c->bi.old_idx_sz = c->calc_idx_sz;
781 c->bi.uncommitted_idx = 0;
782 c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
783 spin_unlock(&c->space_lock);
784 mutex_unlock(&c->tnc_mutex);
786 dbg_cmt("number of index LEBs %d", c->lst.idx_lebs);
787 dbg_cmt("size of index %llu", c->calc_idx_sz);
793 mutex_unlock(&c->tnc_mutex);
798 * write_index - write index nodes.
799 * @c: UBIFS file-system description object
801 * This function writes the index nodes whose positions were laid out in the
802 * layout_in_empty_space function.
804 static int write_index(struct ubifs_info *c)
806 struct ubifs_idx_node *idx;
807 struct ubifs_znode *znode, *cnext;
808 int i, lnum, offs, len, next_len, buf_len, buf_offs, used;
809 int avail, wlen, err, lnum_pos = 0, blen, nxt_offs;
816 * Always write index nodes to the index head so that index nodes and
817 * other types of nodes are never mixed in the same erase block.
819 lnum = c->ihead_lnum;
820 buf_offs = c->ihead_offs;
822 /* Allocate commit buffer */
823 buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size);
827 /* Ensure there is enough room for first write */
828 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
829 if (buf_offs + next_len > c->leb_size) {
830 err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0,
838 u8 hash[UBIFS_HASH_ARR_SZ];
843 idx = c->cbuf + used;
845 /* Make index node */
846 idx->ch.node_type = UBIFS_IDX_NODE;
847 idx->child_cnt = cpu_to_le16(znode->child_cnt);
848 idx->level = cpu_to_le16(znode->level);
849 for (i = 0; i < znode->child_cnt; i++) {
850 struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
851 struct ubifs_zbranch *zbr = &znode->zbranch[i];
853 key_write_idx(c, &zbr->key, &br->key);
854 br->lnum = cpu_to_le32(zbr->lnum);
855 br->offs = cpu_to_le32(zbr->offs);
856 br->len = cpu_to_le32(zbr->len);
857 ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br));
858 if (!zbr->lnum || !zbr->len) {
859 ubifs_err(c, "bad ref in znode");
860 ubifs_dump_znode(c, znode);
862 ubifs_dump_znode(c, zbr->znode);
867 len = ubifs_idx_node_sz(c, znode->child_cnt);
868 ubifs_prepare_node(c, idx, len, 0);
869 ubifs_node_calc_hash(c, idx, hash);
871 mutex_lock(&c->tnc_mutex);
874 ubifs_copy_hash(c, hash,
875 znode->cparent->zbranch[znode->ciip].hash);
878 if (!ubifs_zn_obsolete(znode))
879 ubifs_copy_hash(c, hash,
880 znode->parent->zbranch[znode->iip].hash);
882 ubifs_copy_hash(c, hash, c->zroot.hash);
885 mutex_unlock(&c->tnc_mutex);
887 /* Determine the index node position */
889 lnum = c->ilebs[lnum_pos++];
894 offs = buf_offs + used;
896 if (lnum != znode->lnum || offs != znode->offs ||
898 ubifs_err(c, "inconsistent znode posn");
902 /* Grab some stuff from znode while we still can */
903 cnext = znode->cnext;
905 ubifs_assert(c, ubifs_zn_dirty(znode));
906 ubifs_assert(c, ubifs_zn_cow(znode));
909 * It is important that other threads should see %DIRTY_ZNODE
910 * flag cleared before %COW_ZNODE. Specifically, it matters in
911 * the 'dirty_cow_znode()' function. This is the reason for the
912 * first barrier. Also, we want the bit changes to be seen to
913 * other threads ASAP, to avoid unnecesarry copying, which is
914 * the reason for the second barrier.
916 clear_bit(DIRTY_ZNODE, &znode->flags);
917 smp_mb__before_atomic();
918 clear_bit(COW_ZNODE, &znode->flags);
919 smp_mb__after_atomic();
922 * We have marked the znode as clean but have not updated the
923 * @c->clean_zn_cnt counter. If this znode becomes dirty again
924 * before 'free_obsolete_znodes()' is called, then
925 * @c->clean_zn_cnt will be decremented before it gets
926 * incremented (resulting in 2 decrements for the same znode).
927 * This means that @c->clean_zn_cnt may become negative for a
930 * Q: why we cannot increment @c->clean_zn_cnt?
931 * A: because we do not have the @c->tnc_mutex locked, and the
932 * following code would be racy and buggy:
934 * if (!ubifs_zn_obsolete(znode)) {
935 * atomic_long_inc(&c->clean_zn_cnt);
936 * atomic_long_inc(&ubifs_clean_zn_cnt);
939 * Thus, we just delay the @c->clean_zn_cnt update until we
940 * have the mutex locked.
943 /* Do not access znode from this point on */
945 /* Update buffer positions */
947 used += ALIGN(len, 8);
948 avail -= ALIGN(len, 8);
951 * Calculate the next index node length to see if there is
954 if (cnext == c->cnext)
957 next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
959 nxt_offs = buf_offs + used + next_len;
960 if (next_len && nxt_offs <= c->leb_size) {
966 wlen = ALIGN(wlen, 8);
967 blen = ALIGN(wlen, c->min_io_size);
968 ubifs_pad(c, c->cbuf + wlen, blen - wlen);
971 /* The buffer is full or there are no more znodes to do */
972 err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, blen);
977 if (nxt_offs > c->leb_size) {
978 err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0,
987 avail = buf_len - used;
988 memmove(c->cbuf, c->cbuf + blen, used);
994 if (lnum != c->dbg->new_ihead_lnum ||
995 buf_offs != c->dbg->new_ihead_offs) {
996 ubifs_err(c, "inconsistent ihead");
1000 c->ihead_lnum = lnum;
1001 c->ihead_offs = buf_offs;
1007 * free_obsolete_znodes - free obsolete znodes.
1008 * @c: UBIFS file-system description object
1010 * At the end of commit end, obsolete znodes are freed.
1012 static void free_obsolete_znodes(struct ubifs_info *c)
1014 struct ubifs_znode *znode, *cnext;
1019 cnext = znode->cnext;
1020 if (ubifs_zn_obsolete(znode))
1023 znode->cnext = NULL;
1024 atomic_long_inc(&c->clean_zn_cnt);
1025 atomic_long_inc(&ubifs_clean_zn_cnt);
1027 } while (cnext != c->cnext);
1031 * return_gap_lebs - return LEBs used by the in-gap commit method.
1032 * @c: UBIFS file-system description object
1034 * This function clears the "taken" flag for the LEBs which were used by the
1035 * "commit in-the-gaps" method.
1037 static int return_gap_lebs(struct ubifs_info *c)
1045 for (p = c->gap_lebs; *p != -1; p++) {
1046 err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0,
1058 * ubifs_tnc_end_commit - update the TNC for commit end.
1059 * @c: UBIFS file-system description object
1061 * Write the dirty znodes.
1063 int ubifs_tnc_end_commit(struct ubifs_info *c)
1070 err = return_gap_lebs(c);
1074 err = write_index(c);
1078 mutex_lock(&c->tnc_mutex);
1080 dbg_cmt("TNC height is %d", c->zroot.znode->level + 1);
1082 free_obsolete_znodes(c);
1088 mutex_unlock(&c->tnc_mutex);