• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
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  */
get_heap_comp_val(struct ubifs_lprops * lprops,int cat)38 static 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  */
move_up_lpt_heap(struct ubifs_info * c,struct ubifs_lpt_heap * heap,struct ubifs_lprops * lprops,int cat)62 static 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  */
adjust_lpt_heap(struct ubifs_info * c,struct ubifs_lpt_heap * heap,struct ubifs_lprops * lprops,int hpos,int cat)99 static 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  */
add_to_lpt_heap(struct ubifs_info * c,struct ubifs_lprops * lprops,int cat)178 static 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  */
remove_from_lpt_heap(struct ubifs_info * c,struct ubifs_lprops * lprops,int cat)226 static 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  */
lpt_heap_replace(struct ubifs_info * c,struct ubifs_lprops * old_lprops,struct ubifs_lprops * new_lprops,int cat)256 static 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  */
ubifs_add_to_cat(struct ubifs_info * c,struct ubifs_lprops * lprops,int cat)275 void 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 un-categorized */
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 
304 	lprops->flags &= ~LPROPS_CAT_MASK;
305 	lprops->flags |= cat;
306 	c->in_a_category_cnt += 1;
307 	ubifs_assert(c->in_a_category_cnt <= c->main_lebs);
308 }
309 
310 /**
311  * ubifs_remove_from_cat - remove LEB properties from a category list or heap.
312  * @c: UBIFS file-system description object
313  * @lprops: LEB properties to remove
314  * @cat: LEB category from which to remove
315  *
316  * LEB properties are categorized to enable fast find operations.
317  */
ubifs_remove_from_cat(struct ubifs_info * c,struct ubifs_lprops * lprops,int cat)318 static void ubifs_remove_from_cat(struct ubifs_info *c,
319 				  struct ubifs_lprops *lprops, int cat)
320 {
321 	switch (cat) {
322 	case LPROPS_DIRTY:
323 	case LPROPS_DIRTY_IDX:
324 	case LPROPS_FREE:
325 		remove_from_lpt_heap(c, lprops, cat);
326 		break;
327 	case LPROPS_FREEABLE:
328 		c->freeable_cnt -= 1;
329 		ubifs_assert(c->freeable_cnt >= 0);
330 		/* Fall through */
331 	case LPROPS_UNCAT:
332 	case LPROPS_EMPTY:
333 	case LPROPS_FRDI_IDX:
334 		ubifs_assert(!list_empty(&lprops->list));
335 		list_del(&lprops->list);
336 		break;
337 	default:
338 		ubifs_assert(0);
339 	}
340 
341 	c->in_a_category_cnt -= 1;
342 	ubifs_assert(c->in_a_category_cnt >= 0);
343 }
344 
345 /**
346  * ubifs_replace_cat - replace lprops in a category list or heap.
347  * @c: UBIFS file-system description object
348  * @old_lprops: LEB properties to replace
349  * @new_lprops: LEB properties with which to replace
350  *
351  * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
352  * and the lprops that the pnode contains. When that happens, references in
353  * category lists and heaps must be replaced. This function does that.
354  */
ubifs_replace_cat(struct ubifs_info * c,struct ubifs_lprops * old_lprops,struct ubifs_lprops * new_lprops)355 void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
356 		       struct ubifs_lprops *new_lprops)
357 {
358 	int cat;
359 
360 	cat = new_lprops->flags & LPROPS_CAT_MASK;
361 	switch (cat) {
362 	case LPROPS_DIRTY:
363 	case LPROPS_DIRTY_IDX:
364 	case LPROPS_FREE:
365 		lpt_heap_replace(c, old_lprops, new_lprops, cat);
366 		break;
367 	case LPROPS_UNCAT:
368 	case LPROPS_EMPTY:
369 	case LPROPS_FREEABLE:
370 	case LPROPS_FRDI_IDX:
371 		list_replace(&old_lprops->list, &new_lprops->list);
372 		break;
373 	default:
374 		ubifs_assert(0);
375 	}
376 }
377 
378 /**
379  * ubifs_ensure_cat - ensure LEB properties are categorized.
380  * @c: UBIFS file-system description object
381  * @lprops: LEB properties
382  *
383  * A LEB may have fallen off of the bottom of a heap, and ended up as
384  * un-categorized even though it has enough space for us now. If that is the
385  * case this function will put the LEB back onto a heap.
386  */
ubifs_ensure_cat(struct ubifs_info * c,struct ubifs_lprops * lprops)387 void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
388 {
389 	int cat = lprops->flags & LPROPS_CAT_MASK;
390 
391 	if (cat != LPROPS_UNCAT)
392 		return;
393 	cat = ubifs_categorize_lprops(c, lprops);
394 	if (cat == LPROPS_UNCAT)
395 		return;
396 	ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT);
397 	ubifs_add_to_cat(c, lprops, cat);
398 }
399 
400 /**
401  * ubifs_categorize_lprops - categorize LEB properties.
402  * @c: UBIFS file-system description object
403  * @lprops: LEB properties to categorize
404  *
405  * LEB properties are categorized to enable fast find operations. This function
406  * returns the LEB category to which the LEB properties belong. Note however
407  * that if the LEB category is stored as a heap and the heap is full, the
408  * LEB properties may have their category changed to %LPROPS_UNCAT.
409  */
ubifs_categorize_lprops(const struct ubifs_info * c,const struct ubifs_lprops * lprops)410 int ubifs_categorize_lprops(const struct ubifs_info *c,
411 			    const struct ubifs_lprops *lprops)
412 {
413 	if (lprops->flags & LPROPS_TAKEN)
414 		return LPROPS_UNCAT;
415 
416 	if (lprops->free == c->leb_size) {
417 		ubifs_assert(!(lprops->flags & LPROPS_INDEX));
418 		return LPROPS_EMPTY;
419 	}
420 
421 	if (lprops->free + lprops->dirty == c->leb_size) {
422 		if (lprops->flags & LPROPS_INDEX)
423 			return LPROPS_FRDI_IDX;
424 		else
425 			return LPROPS_FREEABLE;
426 	}
427 
428 	if (lprops->flags & LPROPS_INDEX) {
429 		if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
430 			return LPROPS_DIRTY_IDX;
431 	} else {
432 		if (lprops->dirty >= c->dead_wm &&
433 		    lprops->dirty > lprops->free)
434 			return LPROPS_DIRTY;
435 		if (lprops->free > 0)
436 			return LPROPS_FREE;
437 	}
438 
439 	return LPROPS_UNCAT;
440 }
441 
442 /**
443  * change_category - change LEB properties category.
444  * @c: UBIFS file-system description object
445  * @lprops: LEB properties to re-categorize
446  *
447  * LEB properties are categorized to enable fast find operations. When the LEB
448  * properties change they must be re-categorized.
449  */
change_category(struct ubifs_info * c,struct ubifs_lprops * lprops)450 static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
451 {
452 	int old_cat = lprops->flags & LPROPS_CAT_MASK;
453 	int new_cat = ubifs_categorize_lprops(c, lprops);
454 
455 	if (old_cat == new_cat) {
456 		struct ubifs_lpt_heap *heap;
457 
458 		/* lprops on a heap now must be moved up or down */
459 		if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT)
460 			return; /* Not on a heap */
461 		heap = &c->lpt_heap[new_cat - 1];
462 		adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat);
463 	} else {
464 		ubifs_remove_from_cat(c, lprops, old_cat);
465 		ubifs_add_to_cat(c, lprops, new_cat);
466 	}
467 }
468 
469 /**
470  * ubifs_calc_dark - calculate LEB dark space size.
471  * @c: the UBIFS file-system description object
472  * @spc: amount of free and dirty space in the LEB
473  *
474  * This function calculates and returns amount of dark space in an LEB which
475  * has @spc bytes of free and dirty space.
476  *
477  * UBIFS is trying to account the space which might not be usable, and this
478  * space is called "dark space". For example, if an LEB has only %512 free
479  * bytes, it is dark space, because it cannot fit a large data node.
480  */
ubifs_calc_dark(const struct ubifs_info * c,int spc)481 int ubifs_calc_dark(const struct ubifs_info *c, int spc)
482 {
483 	ubifs_assert(!(spc & 7));
484 
485 	if (spc < c->dark_wm)
486 		return spc;
487 
488 	/*
489 	 * If we have slightly more space then the dark space watermark, we can
490 	 * anyway safely assume it we'll be able to write a node of the
491 	 * smallest size there.
492 	 */
493 	if (spc - c->dark_wm < MIN_WRITE_SZ)
494 		return spc - MIN_WRITE_SZ;
495 
496 	return c->dark_wm;
497 }
498 
499 /**
500  * is_lprops_dirty - determine if LEB properties are dirty.
501  * @c: the UBIFS file-system description object
502  * @lprops: LEB properties to test
503  */
is_lprops_dirty(struct ubifs_info * c,struct ubifs_lprops * lprops)504 static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
505 {
506 	struct ubifs_pnode *pnode;
507 	int pos;
508 
509 	pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1);
510 	pnode = (struct ubifs_pnode *)container_of(lprops - pos,
511 						   struct ubifs_pnode,
512 						   lprops[0]);
513 	return !test_bit(COW_CNODE, &pnode->flags) &&
514 	       test_bit(DIRTY_CNODE, &pnode->flags);
515 }
516 
517 /**
518  * ubifs_change_lp - change LEB properties.
519  * @c: the UBIFS file-system description object
520  * @lp: LEB properties to change
521  * @free: new free space amount
522  * @dirty: new dirty space amount
523  * @flags: new flags
524  * @idx_gc_cnt: change to the count of @idx_gc list
525  *
526  * This function changes LEB properties (@free, @dirty or @flag). However, the
527  * property which has the %LPROPS_NC value is not changed. Returns a pointer to
528  * the updated LEB properties on success and a negative error code on failure.
529  *
530  * Note, the LEB properties may have had to be copied (due to COW) and
531  * consequently the pointer returned may not be the same as the pointer
532  * passed.
533  */
ubifs_change_lp(struct ubifs_info * c,const struct ubifs_lprops * lp,int free,int dirty,int flags,int idx_gc_cnt)534 const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
535 					   const struct ubifs_lprops *lp,
536 					   int free, int dirty, int flags,
537 					   int idx_gc_cnt)
538 {
539 	/*
540 	 * This is the only function that is allowed to change lprops, so we
541 	 * discard the "const" qualifier.
542 	 */
543 	struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;
544 
545 	dbg_lp("LEB %d, free %d, dirty %d, flags %d",
546 	       lprops->lnum, free, dirty, flags);
547 
548 	ubifs_assert(mutex_is_locked(&c->lp_mutex));
549 	ubifs_assert(c->lst.empty_lebs >= 0 &&
550 		     c->lst.empty_lebs <= c->main_lebs);
551 	ubifs_assert(c->freeable_cnt >= 0);
552 	ubifs_assert(c->freeable_cnt <= c->main_lebs);
553 	ubifs_assert(c->lst.taken_empty_lebs >= 0);
554 	ubifs_assert(c->lst.taken_empty_lebs <= c->lst.empty_lebs);
555 	ubifs_assert(!(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
556 	ubifs_assert(!(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
557 	ubifs_assert(!(c->lst.total_used & 7));
558 	ubifs_assert(free == LPROPS_NC || free >= 0);
559 	ubifs_assert(dirty == LPROPS_NC || dirty >= 0);
560 
561 	if (!is_lprops_dirty(c, lprops)) {
562 		lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum);
563 		if (IS_ERR(lprops))
564 			return lprops;
565 	} else
566 		ubifs_assert(lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));
567 
568 	ubifs_assert(!(lprops->free & 7) && !(lprops->dirty & 7));
569 
570 	spin_lock(&c->space_lock);
571 	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
572 		c->lst.taken_empty_lebs -= 1;
573 
574 	if (!(lprops->flags & LPROPS_INDEX)) {
575 		int old_spc;
576 
577 		old_spc = lprops->free + lprops->dirty;
578 		if (old_spc < c->dead_wm)
579 			c->lst.total_dead -= old_spc;
580 		else
581 			c->lst.total_dark -= ubifs_calc_dark(c, old_spc);
582 
583 		c->lst.total_used -= c->leb_size - old_spc;
584 	}
585 
586 	if (free != LPROPS_NC) {
587 		free = ALIGN(free, 8);
588 		c->lst.total_free += free - lprops->free;
589 
590 		/* Increase or decrease empty LEBs counter if needed */
591 		if (free == c->leb_size) {
592 			if (lprops->free != c->leb_size)
593 				c->lst.empty_lebs += 1;
594 		} else if (lprops->free == c->leb_size)
595 			c->lst.empty_lebs -= 1;
596 		lprops->free = free;
597 	}
598 
599 	if (dirty != LPROPS_NC) {
600 		dirty = ALIGN(dirty, 8);
601 		c->lst.total_dirty += dirty - lprops->dirty;
602 		lprops->dirty = dirty;
603 	}
604 
605 	if (flags != LPROPS_NC) {
606 		/* Take care about indexing LEBs counter if needed */
607 		if ((lprops->flags & LPROPS_INDEX)) {
608 			if (!(flags & LPROPS_INDEX))
609 				c->lst.idx_lebs -= 1;
610 		} else if (flags & LPROPS_INDEX)
611 			c->lst.idx_lebs += 1;
612 		lprops->flags = flags;
613 	}
614 
615 	if (!(lprops->flags & LPROPS_INDEX)) {
616 		int new_spc;
617 
618 		new_spc = lprops->free + lprops->dirty;
619 		if (new_spc < c->dead_wm)
620 			c->lst.total_dead += new_spc;
621 		else
622 			c->lst.total_dark += ubifs_calc_dark(c, new_spc);
623 
624 		c->lst.total_used += c->leb_size - new_spc;
625 	}
626 
627 	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
628 		c->lst.taken_empty_lebs += 1;
629 
630 	change_category(c, lprops);
631 	c->idx_gc_cnt += idx_gc_cnt;
632 	spin_unlock(&c->space_lock);
633 	return lprops;
634 }
635 
636 /**
637  * ubifs_get_lp_stats - get lprops statistics.
638  * @c: UBIFS file-system description object
639  * @lst: return statistics
640  */
ubifs_get_lp_stats(struct ubifs_info * c,struct ubifs_lp_stats * lst)641 void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst)
642 {
643 	spin_lock(&c->space_lock);
644 	memcpy(lst, &c->lst, sizeof(struct ubifs_lp_stats));
645 	spin_unlock(&c->space_lock);
646 }
647 
648 /**
649  * ubifs_change_one_lp - change LEB properties.
650  * @c: the UBIFS file-system description object
651  * @lnum: LEB to change properties for
652  * @free: amount of free space
653  * @dirty: amount of dirty space
654  * @flags_set: flags to set
655  * @flags_clean: flags to clean
656  * @idx_gc_cnt: change to the count of idx_gc list
657  *
658  * This function changes properties of LEB @lnum. It is a helper wrapper over
659  * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the
660  * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and
661  * a negative error code in case of failure.
662  */
ubifs_change_one_lp(struct ubifs_info * c,int lnum,int free,int dirty,int flags_set,int flags_clean,int idx_gc_cnt)663 int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
664 			int flags_set, int flags_clean, int idx_gc_cnt)
665 {
666 	int err = 0, flags;
667 	const struct ubifs_lprops *lp;
668 
669 	ubifs_get_lprops(c);
670 
671 	lp = ubifs_lpt_lookup_dirty(c, lnum);
672 	if (IS_ERR(lp)) {
673 		err = PTR_ERR(lp);
674 		goto out;
675 	}
676 
677 	flags = (lp->flags | flags_set) & ~flags_clean;
678 	lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt);
679 	if (IS_ERR(lp))
680 		err = PTR_ERR(lp);
681 
682 out:
683 	ubifs_release_lprops(c);
684 	if (err)
685 		ubifs_err(c, "cannot change properties of LEB %d, error %d",
686 			  lnum, err);
687 	return err;
688 }
689 
690 /**
691  * ubifs_update_one_lp - update LEB properties.
692  * @c: the UBIFS file-system description object
693  * @lnum: LEB to change properties for
694  * @free: amount of free space
695  * @dirty: amount of dirty space to add
696  * @flags_set: flags to set
697  * @flags_clean: flags to clean
698  *
699  * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to
700  * current dirty space, not substitutes it.
701  */
ubifs_update_one_lp(struct ubifs_info * c,int lnum,int free,int dirty,int flags_set,int flags_clean)702 int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
703 			int flags_set, int flags_clean)
704 {
705 	int err = 0, flags;
706 	const struct ubifs_lprops *lp;
707 
708 	ubifs_get_lprops(c);
709 
710 	lp = ubifs_lpt_lookup_dirty(c, lnum);
711 	if (IS_ERR(lp)) {
712 		err = PTR_ERR(lp);
713 		goto out;
714 	}
715 
716 	flags = (lp->flags | flags_set) & ~flags_clean;
717 	lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0);
718 	if (IS_ERR(lp))
719 		err = PTR_ERR(lp);
720 
721 out:
722 	ubifs_release_lprops(c);
723 	if (err)
724 		ubifs_err(c, "cannot update properties of LEB %d, error %d",
725 			  lnum, err);
726 	return err;
727 }
728 
729 /**
730  * ubifs_read_one_lp - read LEB properties.
731  * @c: the UBIFS file-system description object
732  * @lnum: LEB to read properties for
733  * @lp: where to store read properties
734  *
735  * This helper function reads properties of a LEB @lnum and stores them in @lp.
736  * Returns zero in case of success and a negative error code in case of
737  * failure.
738  */
ubifs_read_one_lp(struct ubifs_info * c,int lnum,struct ubifs_lprops * lp)739 int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp)
740 {
741 	int err = 0;
742 	const struct ubifs_lprops *lpp;
743 
744 	ubifs_get_lprops(c);
745 
746 	lpp = ubifs_lpt_lookup(c, lnum);
747 	if (IS_ERR(lpp)) {
748 		err = PTR_ERR(lpp);
749 		ubifs_err(c, "cannot read properties of LEB %d, error %d",
750 			  lnum, err);
751 		goto out;
752 	}
753 
754 	memcpy(lp, lpp, sizeof(struct ubifs_lprops));
755 
756 out:
757 	ubifs_release_lprops(c);
758 	return err;
759 }
760 
761 /**
762  * ubifs_fast_find_free - try to find a LEB with free space quickly.
763  * @c: the UBIFS file-system description object
764  *
765  * This function returns LEB properties for a LEB with free space or %NULL if
766  * the function is unable to find a LEB quickly.
767  */
ubifs_fast_find_free(struct ubifs_info * c)768 const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c)
769 {
770 	struct ubifs_lprops *lprops;
771 	struct ubifs_lpt_heap *heap;
772 
773 	ubifs_assert(mutex_is_locked(&c->lp_mutex));
774 
775 	heap = &c->lpt_heap[LPROPS_FREE - 1];
776 	if (heap->cnt == 0)
777 		return NULL;
778 
779 	lprops = heap->arr[0];
780 	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
781 	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
782 	return lprops;
783 }
784 
785 /**
786  * ubifs_fast_find_empty - try to find an empty LEB quickly.
787  * @c: the UBIFS file-system description object
788  *
789  * This function returns LEB properties for an empty LEB or %NULL if the
790  * function is unable to find an empty LEB quickly.
791  */
ubifs_fast_find_empty(struct ubifs_info * c)792 const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c)
793 {
794 	struct ubifs_lprops *lprops;
795 
796 	ubifs_assert(mutex_is_locked(&c->lp_mutex));
797 
798 	if (list_empty(&c->empty_list))
799 		return NULL;
800 
801 	lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list);
802 	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
803 	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
804 	ubifs_assert(lprops->free == c->leb_size);
805 	return lprops;
806 }
807 
808 /**
809  * ubifs_fast_find_freeable - try to find a freeable LEB quickly.
810  * @c: the UBIFS file-system description object
811  *
812  * This function returns LEB properties for a freeable LEB or %NULL if the
813  * function is unable to find a freeable LEB quickly.
814  */
ubifs_fast_find_freeable(struct ubifs_info * c)815 const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c)
816 {
817 	struct ubifs_lprops *lprops;
818 
819 	ubifs_assert(mutex_is_locked(&c->lp_mutex));
820 
821 	if (list_empty(&c->freeable_list))
822 		return NULL;
823 
824 	lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list);
825 	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
826 	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
827 	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
828 	ubifs_assert(c->freeable_cnt > 0);
829 	return lprops;
830 }
831 
832 /**
833  * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly.
834  * @c: the UBIFS file-system description object
835  *
836  * This function returns LEB properties for a freeable index LEB or %NULL if the
837  * function is unable to find a freeable index LEB quickly.
838  */
ubifs_fast_find_frdi_idx(struct ubifs_info * c)839 const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c)
840 {
841 	struct ubifs_lprops *lprops;
842 
843 	ubifs_assert(mutex_is_locked(&c->lp_mutex));
844 
845 	if (list_empty(&c->frdi_idx_list))
846 		return NULL;
847 
848 	lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list);
849 	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
850 	ubifs_assert((lprops->flags & LPROPS_INDEX));
851 	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
852 	return lprops;
853 }
854 
855 /*
856  * Everything below is related to debugging.
857  */
858 
859 /**
860  * dbg_check_cats - check category heaps and lists.
861  * @c: UBIFS file-system description object
862  *
863  * This function returns %0 on success and a negative error code on failure.
864  */
dbg_check_cats(struct ubifs_info * c)865 int dbg_check_cats(struct ubifs_info *c)
866 {
867 	struct ubifs_lprops *lprops;
868 	struct list_head *pos;
869 	int i, cat;
870 
871 	if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
872 		return 0;
873 
874 	list_for_each_entry(lprops, &c->empty_list, list) {
875 		if (lprops->free != c->leb_size) {
876 			ubifs_err(c, "non-empty LEB %d on empty list (free %d dirty %d flags %d)",
877 				  lprops->lnum, lprops->free, lprops->dirty,
878 				  lprops->flags);
879 			return -EINVAL;
880 		}
881 		if (lprops->flags & LPROPS_TAKEN) {
882 			ubifs_err(c, "taken LEB %d on empty list (free %d dirty %d flags %d)",
883 				  lprops->lnum, lprops->free, lprops->dirty,
884 				  lprops->flags);
885 			return -EINVAL;
886 		}
887 	}
888 
889 	i = 0;
890 	list_for_each_entry(lprops, &c->freeable_list, list) {
891 		if (lprops->free + lprops->dirty != c->leb_size) {
892 			ubifs_err(c, "non-freeable LEB %d on freeable list (free %d dirty %d flags %d)",
893 				  lprops->lnum, lprops->free, lprops->dirty,
894 				  lprops->flags);
895 			return -EINVAL;
896 		}
897 		if (lprops->flags & LPROPS_TAKEN) {
898 			ubifs_err(c, "taken LEB %d on freeable list (free %d dirty %d flags %d)",
899 				  lprops->lnum, lprops->free, lprops->dirty,
900 				  lprops->flags);
901 			return -EINVAL;
902 		}
903 		i += 1;
904 	}
905 	if (i != c->freeable_cnt) {
906 		ubifs_err(c, "freeable list count %d expected %d", i,
907 			  c->freeable_cnt);
908 		return -EINVAL;
909 	}
910 
911 	i = 0;
912 	list_for_each(pos, &c->idx_gc)
913 		i += 1;
914 	if (i != c->idx_gc_cnt) {
915 		ubifs_err(c, "idx_gc list count %d expected %d", i,
916 			  c->idx_gc_cnt);
917 		return -EINVAL;
918 	}
919 
920 	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
921 		if (lprops->free + lprops->dirty != c->leb_size) {
922 			ubifs_err(c, "non-freeable LEB %d on frdi_idx list (free %d dirty %d flags %d)",
923 				  lprops->lnum, lprops->free, lprops->dirty,
924 				  lprops->flags);
925 			return -EINVAL;
926 		}
927 		if (lprops->flags & LPROPS_TAKEN) {
928 			ubifs_err(c, "taken LEB %d on frdi_idx list (free %d dirty %d flags %d)",
929 				  lprops->lnum, lprops->free, lprops->dirty,
930 				  lprops->flags);
931 			return -EINVAL;
932 		}
933 		if (!(lprops->flags & LPROPS_INDEX)) {
934 			ubifs_err(c, "non-index LEB %d on frdi_idx list (free %d dirty %d flags %d)",
935 				  lprops->lnum, lprops->free, lprops->dirty,
936 				  lprops->flags);
937 			return -EINVAL;
938 		}
939 	}
940 
941 	for (cat = 1; cat <= LPROPS_HEAP_CNT; cat++) {
942 		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
943 
944 		for (i = 0; i < heap->cnt; i++) {
945 			lprops = heap->arr[i];
946 			if (!lprops) {
947 				ubifs_err(c, "null ptr in LPT heap cat %d", cat);
948 				return -EINVAL;
949 			}
950 			if (lprops->hpos != i) {
951 				ubifs_err(c, "bad ptr in LPT heap cat %d", cat);
952 				return -EINVAL;
953 			}
954 			if (lprops->flags & LPROPS_TAKEN) {
955 				ubifs_err(c, "taken LEB in LPT heap cat %d", cat);
956 				return -EINVAL;
957 			}
958 		}
959 	}
960 
961 	return 0;
962 }
963 
dbg_check_heap(struct ubifs_info * c,struct ubifs_lpt_heap * heap,int cat,int add_pos)964 void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
965 		    int add_pos)
966 {
967 	int i = 0, j, err = 0;
968 
969 	if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
970 		return;
971 
972 	for (i = 0; i < heap->cnt; i++) {
973 		struct ubifs_lprops *lprops = heap->arr[i];
974 		struct ubifs_lprops *lp;
975 
976 		if (i != add_pos)
977 			if ((lprops->flags & LPROPS_CAT_MASK) != cat) {
978 				err = 1;
979 				goto out;
980 			}
981 		if (lprops->hpos != i) {
982 			err = 2;
983 			goto out;
984 		}
985 		lp = ubifs_lpt_lookup(c, lprops->lnum);
986 		if (IS_ERR(lp)) {
987 			err = 3;
988 			goto out;
989 		}
990 		if (lprops != lp) {
991 			ubifs_err(c, "lprops %zx lp %zx lprops->lnum %d lp->lnum %d",
992 				  (size_t)lprops, (size_t)lp, lprops->lnum,
993 				  lp->lnum);
994 			err = 4;
995 			goto out;
996 		}
997 		for (j = 0; j < i; j++) {
998 			lp = heap->arr[j];
999 			if (lp == lprops) {
1000 				err = 5;
1001 				goto out;
1002 			}
1003 			if (lp->lnum == lprops->lnum) {
1004 				err = 6;
1005 				goto out;
1006 			}
1007 		}
1008 	}
1009 out:
1010 	if (err) {
1011 		ubifs_err(c, "failed cat %d hpos %d err %d", cat, i, err);
1012 		dump_stack();
1013 		ubifs_dump_heap(c, heap, cat);
1014 	}
1015 }
1016 
1017 /**
1018  * scan_check_cb - scan callback.
1019  * @c: the UBIFS file-system description object
1020  * @lp: LEB properties to scan
1021  * @in_tree: whether the LEB properties are in main memory
1022  * @lst: lprops statistics to update
1023  *
1024  * This function returns a code that indicates whether the scan should continue
1025  * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
1026  * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
1027  * (%LPT_SCAN_STOP).
1028  */
scan_check_cb(struct ubifs_info * c,const struct ubifs_lprops * lp,int in_tree,struct ubifs_lp_stats * lst)1029 static int scan_check_cb(struct ubifs_info *c,
1030 			 const struct ubifs_lprops *lp, int in_tree,
1031 			 struct ubifs_lp_stats *lst)
1032 {
1033 	struct ubifs_scan_leb *sleb;
1034 	struct ubifs_scan_node *snod;
1035 	int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty, ret;
1036 	void *buf = NULL;
1037 
1038 	cat = lp->flags & LPROPS_CAT_MASK;
1039 	if (cat != LPROPS_UNCAT) {
1040 		cat = ubifs_categorize_lprops(c, lp);
1041 		if (cat != (lp->flags & LPROPS_CAT_MASK)) {
1042 			ubifs_err(c, "bad LEB category %d expected %d",
1043 				  (lp->flags & LPROPS_CAT_MASK), cat);
1044 			return -EINVAL;
1045 		}
1046 	}
1047 
1048 	/* Check lp is on its category list (if it has one) */
1049 	if (in_tree) {
1050 		struct list_head *list = NULL;
1051 
1052 		switch (cat) {
1053 		case LPROPS_EMPTY:
1054 			list = &c->empty_list;
1055 			break;
1056 		case LPROPS_FREEABLE:
1057 			list = &c->freeable_list;
1058 			break;
1059 		case LPROPS_FRDI_IDX:
1060 			list = &c->frdi_idx_list;
1061 			break;
1062 		case LPROPS_UNCAT:
1063 			list = &c->uncat_list;
1064 			break;
1065 		}
1066 		if (list) {
1067 			struct ubifs_lprops *lprops;
1068 			int found = 0;
1069 
1070 			list_for_each_entry(lprops, list, list) {
1071 				if (lprops == lp) {
1072 					found = 1;
1073 					break;
1074 				}
1075 			}
1076 			if (!found) {
1077 				ubifs_err(c, "bad LPT list (category %d)", cat);
1078 				return -EINVAL;
1079 			}
1080 		}
1081 	}
1082 
1083 	/* Check lp is on its category heap (if it has one) */
1084 	if (in_tree && cat > 0 && cat <= LPROPS_HEAP_CNT) {
1085 		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
1086 
1087 		if ((lp->hpos != -1 && heap->arr[lp->hpos]->lnum != lnum) ||
1088 		    lp != heap->arr[lp->hpos]) {
1089 			ubifs_err(c, "bad LPT heap (category %d)", cat);
1090 			return -EINVAL;
1091 		}
1092 	}
1093 
1094 	buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
1095 	if (!buf)
1096 		return -ENOMEM;
1097 
1098 	/*
1099 	 * After an unclean unmount, empty and freeable LEBs
1100 	 * may contain garbage - do not scan them.
1101 	 */
1102 	if (lp->free == c->leb_size) {
1103 		lst->empty_lebs += 1;
1104 		lst->total_free += c->leb_size;
1105 		lst->total_dark += ubifs_calc_dark(c, c->leb_size);
1106 		return LPT_SCAN_CONTINUE;
1107 	}
1108 	if (lp->free + lp->dirty == c->leb_size &&
1109 	    !(lp->flags & LPROPS_INDEX)) {
1110 		lst->total_free  += lp->free;
1111 		lst->total_dirty += lp->dirty;
1112 		lst->total_dark  +=  ubifs_calc_dark(c, c->leb_size);
1113 		return LPT_SCAN_CONTINUE;
1114 	}
1115 
1116 	sleb = ubifs_scan(c, lnum, 0, buf, 0);
1117 	if (IS_ERR(sleb)) {
1118 		ret = PTR_ERR(sleb);
1119 		if (ret == -EUCLEAN) {
1120 			ubifs_dump_lprops(c);
1121 			ubifs_dump_budg(c, &c->bi);
1122 		}
1123 		goto out;
1124 	}
1125 
1126 	is_idx = -1;
1127 	list_for_each_entry(snod, &sleb->nodes, list) {
1128 		int found, level = 0;
1129 
1130 		cond_resched();
1131 
1132 		if (is_idx == -1)
1133 			is_idx = (snod->type == UBIFS_IDX_NODE) ? 1 : 0;
1134 
1135 		if (is_idx && snod->type != UBIFS_IDX_NODE) {
1136 			ubifs_err(c, "indexing node in data LEB %d:%d",
1137 				  lnum, snod->offs);
1138 			goto out_destroy;
1139 		}
1140 
1141 		if (snod->type == UBIFS_IDX_NODE) {
1142 			struct ubifs_idx_node *idx = snod->node;
1143 
1144 			key_read(c, ubifs_idx_key(c, idx), &snod->key);
1145 			level = le16_to_cpu(idx->level);
1146 		}
1147 
1148 		found = ubifs_tnc_has_node(c, &snod->key, level, lnum,
1149 					   snod->offs, is_idx);
1150 		if (found) {
1151 			if (found < 0)
1152 				goto out_destroy;
1153 			used += ALIGN(snod->len, 8);
1154 		}
1155 	}
1156 
1157 	free = c->leb_size - sleb->endpt;
1158 	dirty = sleb->endpt - used;
1159 
1160 	if (free > c->leb_size || free < 0 || dirty > c->leb_size ||
1161 	    dirty < 0) {
1162 		ubifs_err(c, "bad calculated accounting for LEB %d: free %d, dirty %d",
1163 			  lnum, free, dirty);
1164 		goto out_destroy;
1165 	}
1166 
1167 	if (lp->free + lp->dirty == c->leb_size &&
1168 	    free + dirty == c->leb_size)
1169 		if ((is_idx && !(lp->flags & LPROPS_INDEX)) ||
1170 		    (!is_idx && free == c->leb_size) ||
1171 		    lp->free == c->leb_size) {
1172 			/*
1173 			 * Empty or freeable LEBs could contain index
1174 			 * nodes from an uncompleted commit due to an
1175 			 * unclean unmount. Or they could be empty for
1176 			 * the same reason. Or it may simply not have been
1177 			 * unmapped.
1178 			 */
1179 			free = lp->free;
1180 			dirty = lp->dirty;
1181 			is_idx = 0;
1182 		    }
1183 
1184 	if (is_idx && lp->free + lp->dirty == free + dirty &&
1185 	    lnum != c->ihead_lnum) {
1186 		/*
1187 		 * After an unclean unmount, an index LEB could have a different
1188 		 * amount of free space than the value recorded by lprops. That
1189 		 * is because the in-the-gaps method may use free space or
1190 		 * create free space (as a side-effect of using ubi_leb_change
1191 		 * and not writing the whole LEB). The incorrect free space
1192 		 * value is not a problem because the index is only ever
1193 		 * allocated empty LEBs, so there will never be an attempt to
1194 		 * write to the free space at the end of an index LEB - except
1195 		 * by the in-the-gaps method for which it is not a problem.
1196 		 */
1197 		free = lp->free;
1198 		dirty = lp->dirty;
1199 	}
1200 
1201 	if (lp->free != free || lp->dirty != dirty)
1202 		goto out_print;
1203 
1204 	if (is_idx && !(lp->flags & LPROPS_INDEX)) {
1205 		if (free == c->leb_size)
1206 			/* Free but not unmapped LEB, it's fine */
1207 			is_idx = 0;
1208 		else {
1209 			ubifs_err(c, "indexing node without indexing flag");
1210 			goto out_print;
1211 		}
1212 	}
1213 
1214 	if (!is_idx && (lp->flags & LPROPS_INDEX)) {
1215 		ubifs_err(c, "data node with indexing flag");
1216 		goto out_print;
1217 	}
1218 
1219 	if (free == c->leb_size)
1220 		lst->empty_lebs += 1;
1221 
1222 	if (is_idx)
1223 		lst->idx_lebs += 1;
1224 
1225 	if (!(lp->flags & LPROPS_INDEX))
1226 		lst->total_used += c->leb_size - free - dirty;
1227 	lst->total_free += free;
1228 	lst->total_dirty += dirty;
1229 
1230 	if (!(lp->flags & LPROPS_INDEX)) {
1231 		int spc = free + dirty;
1232 
1233 		if (spc < c->dead_wm)
1234 			lst->total_dead += spc;
1235 		else
1236 			lst->total_dark += ubifs_calc_dark(c, spc);
1237 	}
1238 
1239 	ubifs_scan_destroy(sleb);
1240 	vfree(buf);
1241 	return LPT_SCAN_CONTINUE;
1242 
1243 out_print:
1244 	ubifs_err(c, "bad accounting of LEB %d: free %d, dirty %d flags %#x, should be free %d, dirty %d",
1245 		  lnum, lp->free, lp->dirty, lp->flags, free, dirty);
1246 	ubifs_dump_leb(c, lnum);
1247 out_destroy:
1248 	ubifs_scan_destroy(sleb);
1249 	ret = -EINVAL;
1250 out:
1251 	vfree(buf);
1252 	return ret;
1253 }
1254 
1255 /**
1256  * dbg_check_lprops - check all LEB properties.
1257  * @c: UBIFS file-system description object
1258  *
1259  * This function checks all LEB properties and makes sure they are all correct.
1260  * It returns zero if everything is fine, %-EINVAL if there is an inconsistency
1261  * and other negative error codes in case of other errors. This function is
1262  * called while the file system is locked (because of commit start), so no
1263  * additional locking is required. Note that locking the LPT mutex would cause
1264  * a circular lock dependency with the TNC mutex.
1265  */
dbg_check_lprops(struct ubifs_info * c)1266 int dbg_check_lprops(struct ubifs_info *c)
1267 {
1268 	int i, err;
1269 	struct ubifs_lp_stats lst;
1270 
1271 	if (!dbg_is_chk_lprops(c))
1272 		return 0;
1273 
1274 	/*
1275 	 * As we are going to scan the media, the write buffers have to be
1276 	 * synchronized.
1277 	 */
1278 	for (i = 0; i < c->jhead_cnt; i++) {
1279 		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1280 		if (err)
1281 			return err;
1282 	}
1283 
1284 	memset(&lst, 0, sizeof(struct ubifs_lp_stats));
1285 	err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
1286 				    (ubifs_lpt_scan_callback)scan_check_cb,
1287 				    &lst);
1288 	if (err && err != -ENOSPC)
1289 		goto out;
1290 
1291 	if (lst.empty_lebs != c->lst.empty_lebs ||
1292 	    lst.idx_lebs != c->lst.idx_lebs ||
1293 	    lst.total_free != c->lst.total_free ||
1294 	    lst.total_dirty != c->lst.total_dirty ||
1295 	    lst.total_used != c->lst.total_used) {
1296 		ubifs_err(c, "bad overall accounting");
1297 		ubifs_err(c, "calculated: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld",
1298 			  lst.empty_lebs, lst.idx_lebs, lst.total_free,
1299 			  lst.total_dirty, lst.total_used);
1300 		ubifs_err(c, "read from lprops: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld",
1301 			  c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
1302 			  c->lst.total_dirty, c->lst.total_used);
1303 		err = -EINVAL;
1304 		goto out;
1305 	}
1306 
1307 	if (lst.total_dead != c->lst.total_dead ||
1308 	    lst.total_dark != c->lst.total_dark) {
1309 		ubifs_err(c, "bad dead/dark space accounting");
1310 		ubifs_err(c, "calculated: total_dead %lld, total_dark %lld",
1311 			  lst.total_dead, lst.total_dark);
1312 		ubifs_err(c, "read from lprops: total_dead %lld, total_dark %lld",
1313 			  c->lst.total_dead, c->lst.total_dark);
1314 		err = -EINVAL;
1315 		goto out;
1316 	}
1317 
1318 	err = dbg_check_cats(c);
1319 out:
1320 	return err;
1321 }
1322