blob: 8ce4949fcf4dc8d0de8ae5576fabe0f6ecea9139 [file] [log] [blame]
Stefan Roese9eefe2a2009-03-19 15:35:05 +01001/*
2 * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 *
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.
9 *
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.
14 *
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
18 *
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
21 */
22
23/*
24 * This file implements the functions that access LEB properties and their
25 * categories. LEBs are categorized based on the needs of UBIFS, and the
26 * categories are stored as either heaps or lists to provide a fast way of
27 * finding a LEB in a particular category. For example, UBIFS may need to find
28 * an empty LEB for the journal, or a very dirty LEB for garbage collection.
29 */
30
31#include "ubifs.h"
32
33/**
34 * get_heap_comp_val - get the LEB properties value for heap comparisons.
35 * @lprops: LEB properties
36 * @cat: LEB category
37 */
38static int get_heap_comp_val(struct ubifs_lprops *lprops, int cat)
39{
40 switch (cat) {
41 case LPROPS_FREE:
42 return lprops->free;
43 case LPROPS_DIRTY_IDX:
44 return lprops->free + lprops->dirty;
45 default:
46 return lprops->dirty;
47 }
48}
49
50/**
51 * move_up_lpt_heap - move a new heap entry up as far as possible.
52 * @c: UBIFS file-system description object
53 * @heap: LEB category heap
54 * @lprops: LEB properties to move
55 * @cat: LEB category
56 *
57 * New entries to a heap are added at the bottom and then moved up until the
58 * parent's value is greater. In the case of LPT's category heaps, the value
59 * is either the amount of free space or the amount of dirty space, depending
60 * on the category.
61 */
62static void move_up_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
63 struct ubifs_lprops *lprops, int cat)
64{
65 int val1, val2, hpos;
66
67 hpos = lprops->hpos;
68 if (!hpos)
69 return; /* Already top of the heap */
70 val1 = get_heap_comp_val(lprops, cat);
71 /* Compare to parent and, if greater, move up the heap */
72 do {
73 int ppos = (hpos - 1) / 2;
74
75 val2 = get_heap_comp_val(heap->arr[ppos], cat);
76 if (val2 >= val1)
77 return;
78 /* Greater than parent so move up */
79 heap->arr[ppos]->hpos = hpos;
80 heap->arr[hpos] = heap->arr[ppos];
81 heap->arr[ppos] = lprops;
82 lprops->hpos = ppos;
83 hpos = ppos;
84 } while (hpos);
85}
86
87/**
88 * adjust_lpt_heap - move a changed heap entry up or down the heap.
89 * @c: UBIFS file-system description object
90 * @heap: LEB category heap
91 * @lprops: LEB properties to move
92 * @hpos: heap position of @lprops
93 * @cat: LEB category
94 *
95 * Changed entries in a heap are moved up or down until the parent's value is
96 * greater. In the case of LPT's category heaps, the value is either the amount
97 * of free space or the amount of dirty space, depending on the category.
98 */
99static void adjust_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
100 struct ubifs_lprops *lprops, int hpos, int cat)
101{
102 int val1, val2, val3, cpos;
103
104 val1 = get_heap_comp_val(lprops, cat);
105 /* Compare to parent and, if greater than parent, move up the heap */
106 if (hpos) {
107 int ppos = (hpos - 1) / 2;
108
109 val2 = get_heap_comp_val(heap->arr[ppos], cat);
110 if (val1 > val2) {
111 /* Greater than parent so move up */
112 while (1) {
113 heap->arr[ppos]->hpos = hpos;
114 heap->arr[hpos] = heap->arr[ppos];
115 heap->arr[ppos] = lprops;
116 lprops->hpos = ppos;
117 hpos = ppos;
118 if (!hpos)
119 return;
120 ppos = (hpos - 1) / 2;
121 val2 = get_heap_comp_val(heap->arr[ppos], cat);
122 if (val1 <= val2)
123 return;
124 /* Still greater than parent so keep going */
125 }
126 }
127 }
128
129 /* Not greater than parent, so compare to children */
130 while (1) {
131 /* Compare to left child */
132 cpos = hpos * 2 + 1;
133 if (cpos >= heap->cnt)
134 return;
135 val2 = get_heap_comp_val(heap->arr[cpos], cat);
136 if (val1 < val2) {
137 /* Less than left child, so promote biggest child */
138 if (cpos + 1 < heap->cnt) {
139 val3 = get_heap_comp_val(heap->arr[cpos + 1],
140 cat);
141 if (val3 > val2)
142 cpos += 1; /* Right child is bigger */
143 }
144 heap->arr[cpos]->hpos = hpos;
145 heap->arr[hpos] = heap->arr[cpos];
146 heap->arr[cpos] = lprops;
147 lprops->hpos = cpos;
148 hpos = cpos;
149 continue;
150 }
151 /* Compare to right child */
152 cpos += 1;
153 if (cpos >= heap->cnt)
154 return;
155 val3 = get_heap_comp_val(heap->arr[cpos], cat);
156 if (val1 < val3) {
157 /* Less than right child, so promote right child */
158 heap->arr[cpos]->hpos = hpos;
159 heap->arr[hpos] = heap->arr[cpos];
160 heap->arr[cpos] = lprops;
161 lprops->hpos = cpos;
162 hpos = cpos;
163 continue;
164 }
165 return;
166 }
167}
168
169/**
170 * add_to_lpt_heap - add LEB properties to a LEB category heap.
171 * @c: UBIFS file-system description object
172 * @lprops: LEB properties to add
173 * @cat: LEB category
174 *
175 * This function returns %1 if @lprops is added to the heap for LEB category
176 * @cat, otherwise %0 is returned because the heap is full.
177 */
178static int add_to_lpt_heap(struct ubifs_info *c, struct ubifs_lprops *lprops,
179 int cat)
180{
181 struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
182
183 if (heap->cnt >= heap->max_cnt) {
184 const int b = LPT_HEAP_SZ / 2 - 1;
185 int cpos, val1, val2;
186
187 /* Compare to some other LEB on the bottom of heap */
188 /* Pick a position kind of randomly */
189 cpos = (((size_t)lprops >> 4) & b) + b;
190 ubifs_assert(cpos >= b);
191 ubifs_assert(cpos < LPT_HEAP_SZ);
192 ubifs_assert(cpos < heap->cnt);
193
194 val1 = get_heap_comp_val(lprops, cat);
195 val2 = get_heap_comp_val(heap->arr[cpos], cat);
196 if (val1 > val2) {
197 struct ubifs_lprops *lp;
198
199 lp = heap->arr[cpos];
200 lp->flags &= ~LPROPS_CAT_MASK;
201 lp->flags |= LPROPS_UNCAT;
202 list_add(&lp->list, &c->uncat_list);
203 lprops->hpos = cpos;
204 heap->arr[cpos] = lprops;
205 move_up_lpt_heap(c, heap, lprops, cat);
206 dbg_check_heap(c, heap, cat, lprops->hpos);
207 return 1; /* Added to heap */
208 }
209 dbg_check_heap(c, heap, cat, -1);
210 return 0; /* Not added to heap */
211 } else {
212 lprops->hpos = heap->cnt++;
213 heap->arr[lprops->hpos] = lprops;
214 move_up_lpt_heap(c, heap, lprops, cat);
215 dbg_check_heap(c, heap, cat, lprops->hpos);
216 return 1; /* Added to heap */
217 }
218}
219
220/**
221 * remove_from_lpt_heap - remove LEB properties from a LEB category heap.
222 * @c: UBIFS file-system description object
223 * @lprops: LEB properties to remove
224 * @cat: LEB category
225 */
226static void remove_from_lpt_heap(struct ubifs_info *c,
227 struct ubifs_lprops *lprops, int cat)
228{
229 struct ubifs_lpt_heap *heap;
230 int hpos = lprops->hpos;
231
232 heap = &c->lpt_heap[cat - 1];
233 ubifs_assert(hpos >= 0 && hpos < heap->cnt);
234 ubifs_assert(heap->arr[hpos] == lprops);
235 heap->cnt -= 1;
236 if (hpos < heap->cnt) {
237 heap->arr[hpos] = heap->arr[heap->cnt];
238 heap->arr[hpos]->hpos = hpos;
239 adjust_lpt_heap(c, heap, heap->arr[hpos], hpos, cat);
240 }
241 dbg_check_heap(c, heap, cat, -1);
242}
243
244/**
245 * lpt_heap_replace - replace lprops in a category heap.
246 * @c: UBIFS file-system description object
247 * @old_lprops: LEB properties to replace
248 * @new_lprops: LEB properties with which to replace
249 * @cat: LEB category
250 *
251 * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
252 * and the lprops that the pnode contains. When that happens, references in
253 * the category heaps to those lprops must be updated to point to the new
254 * lprops. This function does that.
255 */
256static void lpt_heap_replace(struct ubifs_info *c,
257 struct ubifs_lprops *old_lprops,
258 struct ubifs_lprops *new_lprops, int cat)
259{
260 struct ubifs_lpt_heap *heap;
261 int hpos = new_lprops->hpos;
262
263 heap = &c->lpt_heap[cat - 1];
264 heap->arr[hpos] = new_lprops;
265}
266
267/**
268 * ubifs_add_to_cat - add LEB properties to a category list or heap.
269 * @c: UBIFS file-system description object
270 * @lprops: LEB properties to add
271 * @cat: LEB category to which to add
272 *
273 * LEB properties are categorized to enable fast find operations.
274 */
275void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
276 int cat)
277{
278 switch (cat) {
279 case LPROPS_DIRTY:
280 case LPROPS_DIRTY_IDX:
281 case LPROPS_FREE:
282 if (add_to_lpt_heap(c, lprops, cat))
283 break;
284 /* No more room on heap so make it uncategorized */
285 cat = LPROPS_UNCAT;
286 /* Fall through */
287 case LPROPS_UNCAT:
288 list_add(&lprops->list, &c->uncat_list);
289 break;
290 case LPROPS_EMPTY:
291 list_add(&lprops->list, &c->empty_list);
292 break;
293 case LPROPS_FREEABLE:
294 list_add(&lprops->list, &c->freeable_list);
295 c->freeable_cnt += 1;
296 break;
297 case LPROPS_FRDI_IDX:
298 list_add(&lprops->list, &c->frdi_idx_list);
299 break;
300 default:
301 ubifs_assert(0);
302 }
303 lprops->flags &= ~LPROPS_CAT_MASK;
304 lprops->flags |= cat;
305}
306
307/**
308 * ubifs_remove_from_cat - remove LEB properties from a category list or heap.
309 * @c: UBIFS file-system description object
310 * @lprops: LEB properties to remove
311 * @cat: LEB category from which to remove
312 *
313 * LEB properties are categorized to enable fast find operations.
314 */
315static void ubifs_remove_from_cat(struct ubifs_info *c,
316 struct ubifs_lprops *lprops, int cat)
317{
318 switch (cat) {
319 case LPROPS_DIRTY:
320 case LPROPS_DIRTY_IDX:
321 case LPROPS_FREE:
322 remove_from_lpt_heap(c, lprops, cat);
323 break;
324 case LPROPS_FREEABLE:
325 c->freeable_cnt -= 1;
326 ubifs_assert(c->freeable_cnt >= 0);
327 /* Fall through */
328 case LPROPS_UNCAT:
329 case LPROPS_EMPTY:
330 case LPROPS_FRDI_IDX:
331 ubifs_assert(!list_empty(&lprops->list));
332 list_del(&lprops->list);
333 break;
334 default:
335 ubifs_assert(0);
336 }
337}
338
339/**
340 * ubifs_replace_cat - replace lprops in a category list or heap.
341 * @c: UBIFS file-system description object
342 * @old_lprops: LEB properties to replace
343 * @new_lprops: LEB properties with which to replace
344 *
345 * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
346 * and the lprops that the pnode contains. When that happens, references in
347 * category lists and heaps must be replaced. This function does that.
348 */
349void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
350 struct ubifs_lprops *new_lprops)
351{
352 int cat;
353
354 cat = new_lprops->flags & LPROPS_CAT_MASK;
355 switch (cat) {
356 case LPROPS_DIRTY:
357 case LPROPS_DIRTY_IDX:
358 case LPROPS_FREE:
359 lpt_heap_replace(c, old_lprops, new_lprops, cat);
360 break;
361 case LPROPS_UNCAT:
362 case LPROPS_EMPTY:
363 case LPROPS_FREEABLE:
364 case LPROPS_FRDI_IDX:
365 list_replace(&old_lprops->list, &new_lprops->list);
366 break;
367 default:
368 ubifs_assert(0);
369 }
370}
371
372/**
373 * ubifs_ensure_cat - ensure LEB properties are categorized.
374 * @c: UBIFS file-system description object
375 * @lprops: LEB properties
376 *
377 * A LEB may have fallen off of the bottom of a heap, and ended up as
378 * uncategorized even though it has enough space for us now. If that is the case
379 * this function will put the LEB back onto a heap.
380 */
381void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
382{
383 int cat = lprops->flags & LPROPS_CAT_MASK;
384
385 if (cat != LPROPS_UNCAT)
386 return;
387 cat = ubifs_categorize_lprops(c, lprops);
388 if (cat == LPROPS_UNCAT)
389 return;
390 ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT);
391 ubifs_add_to_cat(c, lprops, cat);
392}
393
394/**
395 * ubifs_categorize_lprops - categorize LEB properties.
396 * @c: UBIFS file-system description object
397 * @lprops: LEB properties to categorize
398 *
399 * LEB properties are categorized to enable fast find operations. This function
400 * returns the LEB category to which the LEB properties belong. Note however
401 * that if the LEB category is stored as a heap and the heap is full, the
402 * LEB properties may have their category changed to %LPROPS_UNCAT.
403 */
404int ubifs_categorize_lprops(const struct ubifs_info *c,
405 const struct ubifs_lprops *lprops)
406{
407 if (lprops->flags & LPROPS_TAKEN)
408 return LPROPS_UNCAT;
409
410 if (lprops->free == c->leb_size) {
411 ubifs_assert(!(lprops->flags & LPROPS_INDEX));
412 return LPROPS_EMPTY;
413 }
414
415 if (lprops->free + lprops->dirty == c->leb_size) {
416 if (lprops->flags & LPROPS_INDEX)
417 return LPROPS_FRDI_IDX;
418 else
419 return LPROPS_FREEABLE;
420 }
421
422 if (lprops->flags & LPROPS_INDEX) {
423 if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
424 return LPROPS_DIRTY_IDX;
425 } else {
426 if (lprops->dirty >= c->dead_wm &&
427 lprops->dirty > lprops->free)
428 return LPROPS_DIRTY;
429 if (lprops->free > 0)
430 return LPROPS_FREE;
431 }
432
433 return LPROPS_UNCAT;
434}
435
436/**
437 * change_category - change LEB properties category.
438 * @c: UBIFS file-system description object
439 * @lprops: LEB properties to recategorize
440 *
441 * LEB properties are categorized to enable fast find operations. When the LEB
442 * properties change they must be recategorized.
443 */
444static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
445{
446 int old_cat = lprops->flags & LPROPS_CAT_MASK;
447 int new_cat = ubifs_categorize_lprops(c, lprops);
448
449 if (old_cat == new_cat) {
450 struct ubifs_lpt_heap *heap = &c->lpt_heap[new_cat - 1];
451
452 /* lprops on a heap now must be moved up or down */
453 if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT)
454 return; /* Not on a heap */
455 heap = &c->lpt_heap[new_cat - 1];
456 adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat);
457 } else {
458 ubifs_remove_from_cat(c, lprops, old_cat);
459 ubifs_add_to_cat(c, lprops, new_cat);
460 }
461}
462
463/**
464 * calc_dark - calculate LEB dark space size.
465 * @c: the UBIFS file-system description object
466 * @spc: amount of free and dirty space in the LEB
467 *
468 * This function calculates amount of dark space in an LEB which has @spc bytes
469 * of free and dirty space. Returns the calculations result.
470 *
471 * Dark space is the space which is not always usable - it depends on which
472 * nodes are written in which order. E.g., if an LEB has only 512 free bytes,
473 * it is dark space, because it cannot fit a large data node. So UBIFS cannot
474 * count on this LEB and treat these 512 bytes as usable because it is not true
475 * if, for example, only big chunks of uncompressible data will be written to
476 * the FS.
477 */
478static int calc_dark(struct ubifs_info *c, int spc)
479{
480 ubifs_assert(!(spc & 7));
481
482 if (spc < c->dark_wm)
483 return spc;
484
485 /*
486 * If we have slightly more space then the dark space watermark, we can
487 * anyway safely assume it we'll be able to write a node of the
488 * smallest size there.
489 */
490 if (spc - c->dark_wm < MIN_WRITE_SZ)
491 return spc - MIN_WRITE_SZ;
492
493 return c->dark_wm;
494}
495
496/**
497 * is_lprops_dirty - determine if LEB properties are dirty.
498 * @c: the UBIFS file-system description object
499 * @lprops: LEB properties to test
500 */
501static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
502{
503 struct ubifs_pnode *pnode;
504 int pos;
505
506 pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1);
507 pnode = (struct ubifs_pnode *)container_of(lprops - pos,
508 struct ubifs_pnode,
509 lprops[0]);
510 return !test_bit(COW_ZNODE, &pnode->flags) &&
511 test_bit(DIRTY_CNODE, &pnode->flags);
512}
513
514/**
515 * ubifs_change_lp - change LEB properties.
516 * @c: the UBIFS file-system description object
517 * @lp: LEB properties to change
518 * @free: new free space amount
519 * @dirty: new dirty space amount
520 * @flags: new flags
521 * @idx_gc_cnt: change to the count of idx_gc list
522 *
523 * This function changes LEB properties (@free, @dirty or @flag). However, the
524 * property which has the %LPROPS_NC value is not changed. Returns a pointer to
525 * the updated LEB properties on success and a negative error code on failure.
526 *
527 * Note, the LEB properties may have had to be copied (due to COW) and
528 * consequently the pointer returned may not be the same as the pointer
529 * passed.
530 */
531const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
532 const struct ubifs_lprops *lp,
533 int free, int dirty, int flags,
534 int idx_gc_cnt)
535{
536 /*
537 * This is the only function that is allowed to change lprops, so we
538 * discard the const qualifier.
539 */
540 struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;
541
542 dbg_lp("LEB %d, free %d, dirty %d, flags %d",
543 lprops->lnum, free, dirty, flags);
544
545 ubifs_assert(mutex_is_locked(&c->lp_mutex));
546 ubifs_assert(c->lst.empty_lebs >= 0 &&
547 c->lst.empty_lebs <= c->main_lebs);
548 ubifs_assert(c->freeable_cnt >= 0);
549 ubifs_assert(c->freeable_cnt <= c->main_lebs);
550 ubifs_assert(c->lst.taken_empty_lebs >= 0);
551 ubifs_assert(c->lst.taken_empty_lebs <= c->lst.empty_lebs);
552 ubifs_assert(!(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
553 ubifs_assert(!(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
554 ubifs_assert(!(c->lst.total_used & 7));
555 ubifs_assert(free == LPROPS_NC || free >= 0);
556 ubifs_assert(dirty == LPROPS_NC || dirty >= 0);
557
558 if (!is_lprops_dirty(c, lprops)) {
559 lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum);
560 if (IS_ERR(lprops))
561 return lprops;
562 } else
563 ubifs_assert(lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));
564
565 ubifs_assert(!(lprops->free & 7) && !(lprops->dirty & 7));
566
567 spin_lock(&c->space_lock);
568 if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
569 c->lst.taken_empty_lebs -= 1;
570
571 if (!(lprops->flags & LPROPS_INDEX)) {
572 int old_spc;
573
574 old_spc = lprops->free + lprops->dirty;
575 if (old_spc < c->dead_wm)
576 c->lst.total_dead -= old_spc;
577 else
578 c->lst.total_dark -= calc_dark(c, old_spc);
579
580 c->lst.total_used -= c->leb_size - old_spc;
581 }
582
583 if (free != LPROPS_NC) {
584 free = ALIGN(free, 8);
585 c->lst.total_free += free - lprops->free;
586
587 /* Increase or decrease empty LEBs counter if needed */
588 if (free == c->leb_size) {
589 if (lprops->free != c->leb_size)
590 c->lst.empty_lebs += 1;
591 } else if (lprops->free == c->leb_size)
592 c->lst.empty_lebs -= 1;
593 lprops->free = free;
594 }
595
596 if (dirty != LPROPS_NC) {
597 dirty = ALIGN(dirty, 8);
598 c->lst.total_dirty += dirty - lprops->dirty;
599 lprops->dirty = dirty;
600 }
601
602 if (flags != LPROPS_NC) {
603 /* Take care about indexing LEBs counter if needed */
604 if ((lprops->flags & LPROPS_INDEX)) {
605 if (!(flags & LPROPS_INDEX))
606 c->lst.idx_lebs -= 1;
607 } else if (flags & LPROPS_INDEX)
608 c->lst.idx_lebs += 1;
609 lprops->flags = flags;
610 }
611
612 if (!(lprops->flags & LPROPS_INDEX)) {
613 int new_spc;
614
615 new_spc = lprops->free + lprops->dirty;
616 if (new_spc < c->dead_wm)
617 c->lst.total_dead += new_spc;
618 else
619 c->lst.total_dark += calc_dark(c, new_spc);
620
621 c->lst.total_used += c->leb_size - new_spc;
622 }
623
624 if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
625 c->lst.taken_empty_lebs += 1;
626
627 change_category(c, lprops);
628 c->idx_gc_cnt += idx_gc_cnt;
629 spin_unlock(&c->space_lock);
630 return lprops;
631}
632
633/**
634 * ubifs_get_lp_stats - get lprops statistics.
635 * @c: UBIFS file-system description object
636 * @st: return statistics
637 */
638void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst)
639{
640 spin_lock(&c->space_lock);
641 memcpy(lst, &c->lst, sizeof(struct ubifs_lp_stats));
642 spin_unlock(&c->space_lock);
643}
644
645/**
646 * ubifs_change_one_lp - change LEB properties.
647 * @c: the UBIFS file-system description object
648 * @lnum: LEB to change properties for
649 * @free: amount of free space
650 * @dirty: amount of dirty space
651 * @flags_set: flags to set
652 * @flags_clean: flags to clean
653 * @idx_gc_cnt: change to the count of idx_gc list
654 *
655 * This function changes properties of LEB @lnum. It is a helper wrapper over
656 * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the
657 * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and
658 * a negative error code in case of failure.
659 */
660int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
661 int flags_set, int flags_clean, int idx_gc_cnt)
662{
663 int err = 0, flags;
664 const struct ubifs_lprops *lp;
665
666 ubifs_get_lprops(c);
667
668 lp = ubifs_lpt_lookup_dirty(c, lnum);
669 if (IS_ERR(lp)) {
670 err = PTR_ERR(lp);
671 goto out;
672 }
673
674 flags = (lp->flags | flags_set) & ~flags_clean;
675 lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt);
676 if (IS_ERR(lp))
677 err = PTR_ERR(lp);
678
679out:
680 ubifs_release_lprops(c);
681 return err;
682}
683
684/**
685 * ubifs_update_one_lp - update LEB properties.
686 * @c: the UBIFS file-system description object
687 * @lnum: LEB to change properties for
688 * @free: amount of free space
689 * @dirty: amount of dirty space to add
690 * @flags_set: flags to set
691 * @flags_clean: flags to clean
692 *
693 * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to
694 * current dirty space, not substitutes it.
695 */
696int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
697 int flags_set, int flags_clean)
698{
699 int err = 0, flags;
700 const struct ubifs_lprops *lp;
701
702 ubifs_get_lprops(c);
703
704 lp = ubifs_lpt_lookup_dirty(c, lnum);
705 if (IS_ERR(lp)) {
706 err = PTR_ERR(lp);
707 goto out;
708 }
709
710 flags = (lp->flags | flags_set) & ~flags_clean;
711 lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0);
712 if (IS_ERR(lp))
713 err = PTR_ERR(lp);
714
715out:
716 ubifs_release_lprops(c);
717 return err;
718}
719
720/**
721 * ubifs_read_one_lp - read LEB properties.
722 * @c: the UBIFS file-system description object
723 * @lnum: LEB to read properties for
724 * @lp: where to store read properties
725 *
726 * This helper function reads properties of a LEB @lnum and stores them in @lp.
727 * Returns zero in case of success and a negative error code in case of
728 * failure.
729 */
730int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp)
731{
732 int err = 0;
733 const struct ubifs_lprops *lpp;
734
735 ubifs_get_lprops(c);
736
737 lpp = ubifs_lpt_lookup(c, lnum);
738 if (IS_ERR(lpp)) {
739 err = PTR_ERR(lpp);
740 goto out;
741 }
742
743 memcpy(lp, lpp, sizeof(struct ubifs_lprops));
744
745out:
746 ubifs_release_lprops(c);
747 return err;
748}
749
750/**
751 * ubifs_fast_find_free - try to find a LEB with free space quickly.
752 * @c: the UBIFS file-system description object
753 *
754 * This function returns LEB properties for a LEB with free space or %NULL if
755 * the function is unable to find a LEB quickly.
756 */
757const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c)
758{
759 struct ubifs_lprops *lprops;
760 struct ubifs_lpt_heap *heap;
761
762 ubifs_assert(mutex_is_locked(&c->lp_mutex));
763
764 heap = &c->lpt_heap[LPROPS_FREE - 1];
765 if (heap->cnt == 0)
766 return NULL;
767
768 lprops = heap->arr[0];
769 ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
770 ubifs_assert(!(lprops->flags & LPROPS_INDEX));
771 return lprops;
772}
773
774/**
775 * ubifs_fast_find_empty - try to find an empty LEB quickly.
776 * @c: the UBIFS file-system description object
777 *
778 * This function returns LEB properties for an empty LEB or %NULL if the
779 * function is unable to find an empty LEB quickly.
780 */
781const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c)
782{
783 struct ubifs_lprops *lprops;
784
785 ubifs_assert(mutex_is_locked(&c->lp_mutex));
786
787 if (list_empty(&c->empty_list))
788 return NULL;
789
790 lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list);
791 ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
792 ubifs_assert(!(lprops->flags & LPROPS_INDEX));
793 ubifs_assert(lprops->free == c->leb_size);
794 return lprops;
795}
796
797/**
798 * ubifs_fast_find_freeable - try to find a freeable LEB quickly.
799 * @c: the UBIFS file-system description object
800 *
801 * This function returns LEB properties for a freeable LEB or %NULL if the
802 * function is unable to find a freeable LEB quickly.
803 */
804const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c)
805{
806 struct ubifs_lprops *lprops;
807
808 ubifs_assert(mutex_is_locked(&c->lp_mutex));
809
810 if (list_empty(&c->freeable_list))
811 return NULL;
812
813 lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list);
814 ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
815 ubifs_assert(!(lprops->flags & LPROPS_INDEX));
816 ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
817 ubifs_assert(c->freeable_cnt > 0);
818 return lprops;
819}
820
821/**
822 * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly.
823 * @c: the UBIFS file-system description object
824 *
825 * This function returns LEB properties for a freeable index LEB or %NULL if the
826 * function is unable to find a freeable index LEB quickly.
827 */
828const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c)
829{
830 struct ubifs_lprops *lprops;
831
832 ubifs_assert(mutex_is_locked(&c->lp_mutex));
833
834 if (list_empty(&c->frdi_idx_list))
835 return NULL;
836
837 lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list);
838 ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
839 ubifs_assert((lprops->flags & LPROPS_INDEX));
840 ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
841 return lprops;
842}