lprops.c 36 KB
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/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Authors: Adrian Hunter
 *          Artem Bityutskiy (Битюцкий Артём)
 */

/*
 * This file implements the functions that access LEB properties and their
 * categories. LEBs are categorized based on the needs of UBIFS, and the
 * categories are stored as either heaps or lists to provide a fast way of
 * finding a LEB in a particular category. For example, UBIFS may need to find
 * an empty LEB for the journal, or a very dirty LEB for garbage collection.
 */

#include "ubifs.h"

/**
 * get_heap_comp_val - get the LEB properties value for heap comparisons.
 * @lprops: LEB properties
 * @cat: LEB category
 */
static int get_heap_comp_val(struct ubifs_lprops *lprops, int cat)
{
	switch (cat) {
	case LPROPS_FREE:
		return lprops->free;
	case LPROPS_DIRTY_IDX:
		return lprops->free + lprops->dirty;
	default:
		return lprops->dirty;
	}
}

/**
 * move_up_lpt_heap - move a new heap entry up as far as possible.
 * @c: UBIFS file-system description object
 * @heap: LEB category heap
 * @lprops: LEB properties to move
 * @cat: LEB category
 *
 * New entries to a heap are added at the bottom and then moved up until the
 * parent's value is greater.  In the case of LPT's category heaps, the value
 * is either the amount of free space or the amount of dirty space, depending
 * on the category.
 */
static void move_up_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
			     struct ubifs_lprops *lprops, int cat)
{
	int val1, val2, hpos;

	hpos = lprops->hpos;
	if (!hpos)
		return; /* Already top of the heap */
	val1 = get_heap_comp_val(lprops, cat);
	/* Compare to parent and, if greater, move up the heap */
	do {
		int ppos = (hpos - 1) / 2;

		val2 = get_heap_comp_val(heap->arr[ppos], cat);
		if (val2 >= val1)
			return;
		/* Greater than parent so move up */
		heap->arr[ppos]->hpos = hpos;
		heap->arr[hpos] = heap->arr[ppos];
		heap->arr[ppos] = lprops;
		lprops->hpos = ppos;
		hpos = ppos;
	} while (hpos);
}

/**
 * adjust_lpt_heap - move a changed heap entry up or down the heap.
 * @c: UBIFS file-system description object
 * @heap: LEB category heap
 * @lprops: LEB properties to move
 * @hpos: heap position of @lprops
 * @cat: LEB category
 *
 * Changed entries in a heap are moved up or down until the parent's value is
 * greater.  In the case of LPT's category heaps, the value is either the amount
 * of free space or the amount of dirty space, depending on the category.
 */
static void adjust_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
			    struct ubifs_lprops *lprops, int hpos, int cat)
{
	int val1, val2, val3, cpos;

	val1 = get_heap_comp_val(lprops, cat);
	/* Compare to parent and, if greater than parent, move up the heap */
	if (hpos) {
		int ppos = (hpos - 1) / 2;

		val2 = get_heap_comp_val(heap->arr[ppos], cat);
		if (val1 > val2) {
			/* Greater than parent so move up */
			while (1) {
				heap->arr[ppos]->hpos = hpos;
				heap->arr[hpos] = heap->arr[ppos];
				heap->arr[ppos] = lprops;
				lprops->hpos = ppos;
				hpos = ppos;
				if (!hpos)
					return;
				ppos = (hpos - 1) / 2;
				val2 = get_heap_comp_val(heap->arr[ppos], cat);
				if (val1 <= val2)
					return;
				/* Still greater than parent so keep going */
			}
		}
	}
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	/* Not greater than parent, so compare to children */
	while (1) {
		/* Compare to left child */
		cpos = hpos * 2 + 1;
		if (cpos >= heap->cnt)
			return;
		val2 = get_heap_comp_val(heap->arr[cpos], cat);
		if (val1 < val2) {
			/* Less than left child, so promote biggest child */
			if (cpos + 1 < heap->cnt) {
				val3 = get_heap_comp_val(heap->arr[cpos + 1],
							 cat);
				if (val3 > val2)
					cpos += 1; /* Right child is bigger */
			}
			heap->arr[cpos]->hpos = hpos;
			heap->arr[hpos] = heap->arr[cpos];
			heap->arr[cpos] = lprops;
			lprops->hpos = cpos;
			hpos = cpos;
			continue;
		}
		/* Compare to right child */
		cpos += 1;
		if (cpos >= heap->cnt)
			return;
		val3 = get_heap_comp_val(heap->arr[cpos], cat);
		if (val1 < val3) {
			/* Less than right child, so promote right child */
			heap->arr[cpos]->hpos = hpos;
			heap->arr[hpos] = heap->arr[cpos];
			heap->arr[cpos] = lprops;
			lprops->hpos = cpos;
			hpos = cpos;
			continue;
		}
		return;
	}
}

/**
 * add_to_lpt_heap - add LEB properties to a LEB category heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to add
 * @cat: LEB category
 *
 * This function returns %1 if @lprops is added to the heap for LEB category
 * @cat, otherwise %0 is returned because the heap is full.
 */
static int add_to_lpt_heap(struct ubifs_info *c, struct ubifs_lprops *lprops,
			   int cat)
{
	struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];

	if (heap->cnt >= heap->max_cnt) {
		const int b = LPT_HEAP_SZ / 2 - 1;
		int cpos, val1, val2;

		/* Compare to some other LEB on the bottom of heap */
		/* Pick a position kind of randomly */
		cpos = (((size_t)lprops >> 4) & b) + b;
		ubifs_assert(cpos >= b);
		ubifs_assert(cpos < LPT_HEAP_SZ);
		ubifs_assert(cpos < heap->cnt);

		val1 = get_heap_comp_val(lprops, cat);
		val2 = get_heap_comp_val(heap->arr[cpos], cat);
		if (val1 > val2) {
			struct ubifs_lprops *lp;

			lp = heap->arr[cpos];
			lp->flags &= ~LPROPS_CAT_MASK;
			lp->flags |= LPROPS_UNCAT;
			list_add(&lp->list, &c->uncat_list);
			lprops->hpos = cpos;
			heap->arr[cpos] = lprops;
			move_up_lpt_heap(c, heap, lprops, cat);
			dbg_check_heap(c, heap, cat, lprops->hpos);
			return 1; /* Added to heap */
		}
		dbg_check_heap(c, heap, cat, -1);
		return 0; /* Not added to heap */
	} else {
		lprops->hpos = heap->cnt++;
		heap->arr[lprops->hpos] = lprops;
		move_up_lpt_heap(c, heap, lprops, cat);
		dbg_check_heap(c, heap, cat, lprops->hpos);
		return 1; /* Added to heap */
	}
}

/**
 * remove_from_lpt_heap - remove LEB properties from a LEB category heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to remove
 * @cat: LEB category
 */
static void remove_from_lpt_heap(struct ubifs_info *c,
				 struct ubifs_lprops *lprops, int cat)
{
	struct ubifs_lpt_heap *heap;
	int hpos = lprops->hpos;

	heap = &c->lpt_heap[cat - 1];
	ubifs_assert(hpos >= 0 && hpos < heap->cnt);
	ubifs_assert(heap->arr[hpos] == lprops);
	heap->cnt -= 1;
	if (hpos < heap->cnt) {
		heap->arr[hpos] = heap->arr[heap->cnt];
		heap->arr[hpos]->hpos = hpos;
		adjust_lpt_heap(c, heap, heap->arr[hpos], hpos, cat);
	}
	dbg_check_heap(c, heap, cat, -1);
}

/**
 * lpt_heap_replace - replace lprops in a category heap.
 * @c: UBIFS file-system description object
 * @old_lprops: LEB properties to replace
 * @new_lprops: LEB properties with which to replace
 * @cat: LEB category
 *
 * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
 * and the lprops that the pnode contains.  When that happens, references in
 * the category heaps to those lprops must be updated to point to the new
 * lprops.  This function does that.
 */
static void lpt_heap_replace(struct ubifs_info *c,
			     struct ubifs_lprops *old_lprops,
			     struct ubifs_lprops *new_lprops, int cat)
{
	struct ubifs_lpt_heap *heap;
	int hpos = new_lprops->hpos;

	heap = &c->lpt_heap[cat - 1];
	heap->arr[hpos] = new_lprops;
}

/**
 * ubifs_add_to_cat - add LEB properties to a category list or heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to add
 * @cat: LEB category to which to add
 *
 * LEB properties are categorized to enable fast find operations.
 */
void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
		      int cat)
{
	switch (cat) {
	case LPROPS_DIRTY:
	case LPROPS_DIRTY_IDX:
	case LPROPS_FREE:
		if (add_to_lpt_heap(c, lprops, cat))
			break;
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		/* No more room on heap so make it un-categorized */
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		cat = LPROPS_UNCAT;
		/* Fall through */
	case LPROPS_UNCAT:
		list_add(&lprops->list, &c->uncat_list);
		break;
	case LPROPS_EMPTY:
		list_add(&lprops->list, &c->empty_list);
		break;
	case LPROPS_FREEABLE:
		list_add(&lprops->list, &c->freeable_list);
		c->freeable_cnt += 1;
		break;
	case LPROPS_FRDI_IDX:
		list_add(&lprops->list, &c->frdi_idx_list);
		break;
	default:
		ubifs_assert(0);
	}
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	lprops->flags &= ~LPROPS_CAT_MASK;
	lprops->flags |= cat;
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	c->in_a_category_cnt += 1;
	ubifs_assert(c->in_a_category_cnt <= c->main_lebs);
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}

/**
 * ubifs_remove_from_cat - remove LEB properties from a category list or heap.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to remove
 * @cat: LEB category from which to remove
 *
 * LEB properties are categorized to enable fast find operations.
 */
static void ubifs_remove_from_cat(struct ubifs_info *c,
				  struct ubifs_lprops *lprops, int cat)
{
	switch (cat) {
	case LPROPS_DIRTY:
	case LPROPS_DIRTY_IDX:
	case LPROPS_FREE:
		remove_from_lpt_heap(c, lprops, cat);
		break;
	case LPROPS_FREEABLE:
		c->freeable_cnt -= 1;
		ubifs_assert(c->freeable_cnt >= 0);
		/* Fall through */
	case LPROPS_UNCAT:
	case LPROPS_EMPTY:
	case LPROPS_FRDI_IDX:
		ubifs_assert(!list_empty(&lprops->list));
		list_del(&lprops->list);
		break;
	default:
		ubifs_assert(0);
	}
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	c->in_a_category_cnt -= 1;
	ubifs_assert(c->in_a_category_cnt >= 0);
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}

/**
 * ubifs_replace_cat - replace lprops in a category list or heap.
 * @c: UBIFS file-system description object
 * @old_lprops: LEB properties to replace
 * @new_lprops: LEB properties with which to replace
 *
 * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
 * and the lprops that the pnode contains. When that happens, references in
 * category lists and heaps must be replaced. This function does that.
 */
void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
		       struct ubifs_lprops *new_lprops)
{
	int cat;

	cat = new_lprops->flags & LPROPS_CAT_MASK;
	switch (cat) {
	case LPROPS_DIRTY:
	case LPROPS_DIRTY_IDX:
	case LPROPS_FREE:
		lpt_heap_replace(c, old_lprops, new_lprops, cat);
		break;
	case LPROPS_UNCAT:
	case LPROPS_EMPTY:
	case LPROPS_FREEABLE:
	case LPROPS_FRDI_IDX:
		list_replace(&old_lprops->list, &new_lprops->list);
		break;
	default:
		ubifs_assert(0);
	}
}

/**
 * ubifs_ensure_cat - ensure LEB properties are categorized.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties
 *
 * A LEB may have fallen off of the bottom of a heap, and ended up as
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 * un-categorized even though it has enough space for us now. If that is the
 * case this function will put the LEB back onto a heap.
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 */
void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
{
	int cat = lprops->flags & LPROPS_CAT_MASK;

	if (cat != LPROPS_UNCAT)
		return;
	cat = ubifs_categorize_lprops(c, lprops);
	if (cat == LPROPS_UNCAT)
		return;
	ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT);
	ubifs_add_to_cat(c, lprops, cat);
}

/**
 * ubifs_categorize_lprops - categorize LEB properties.
 * @c: UBIFS file-system description object
 * @lprops: LEB properties to categorize
 *
 * LEB properties are categorized to enable fast find operations. This function
 * returns the LEB category to which the LEB properties belong. Note however
 * that if the LEB category is stored as a heap and the heap is full, the
 * LEB properties may have their category changed to %LPROPS_UNCAT.
 */
int ubifs_categorize_lprops(const struct ubifs_info *c,
			    const struct ubifs_lprops *lprops)
{
	if (lprops->flags & LPROPS_TAKEN)
		return LPROPS_UNCAT;

	if (lprops->free == c->leb_size) {
		ubifs_assert(!(lprops->flags & LPROPS_INDEX));
		return LPROPS_EMPTY;
	}

	if (lprops->free + lprops->dirty == c->leb_size) {
		if (lprops->flags & LPROPS_INDEX)
			return LPROPS_FRDI_IDX;
		else
			return LPROPS_FREEABLE;
	}

	if (lprops->flags & LPROPS_INDEX) {
		if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
			return LPROPS_DIRTY_IDX;
	} else {
		if (lprops->dirty >= c->dead_wm &&
		    lprops->dirty > lprops->free)
			return LPROPS_DIRTY;
		if (lprops->free > 0)
			return LPROPS_FREE;
	}

	return LPROPS_UNCAT;
}

/**
 * change_category - change LEB properties category.
 * @c: UBIFS file-system description object
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 * @lprops: LEB properties to re-categorize
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 *
 * LEB properties are categorized to enable fast find operations. When the LEB
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 * properties change they must be re-categorized.
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 */
static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
{
	int old_cat = lprops->flags & LPROPS_CAT_MASK;
	int new_cat = ubifs_categorize_lprops(c, lprops);

	if (old_cat == new_cat) {
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		struct ubifs_lpt_heap *heap;
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		/* lprops on a heap now must be moved up or down */
		if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT)
			return; /* Not on a heap */
		heap = &c->lpt_heap[new_cat - 1];
		adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat);
	} else {
		ubifs_remove_from_cat(c, lprops, old_cat);
		ubifs_add_to_cat(c, lprops, new_cat);
	}
}

/**
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 * ubifs_calc_dark - calculate LEB dark space size.
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 * @c: the UBIFS file-system description object
 * @spc: amount of free and dirty space in the LEB
 *
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 * This function calculates and returns amount of dark space in an LEB which
 * has @spc bytes of free and dirty space.
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 *
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 * UBIFS is trying to account the space which might not be usable, and this
 * space is called "dark space". For example, if an LEB has only %512 free
 * bytes, it is dark space, because it cannot fit a large data node.
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 */
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int ubifs_calc_dark(const struct ubifs_info *c, int spc)
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{
	ubifs_assert(!(spc & 7));

	if (spc < c->dark_wm)
		return spc;

	/*
	 * If we have slightly more space then the dark space watermark, we can
	 * anyway safely assume it we'll be able to write a node of the
	 * smallest size there.
	 */
	if (spc - c->dark_wm < MIN_WRITE_SZ)
		return spc - MIN_WRITE_SZ;

	return c->dark_wm;
}

/**
 * is_lprops_dirty - determine if LEB properties are dirty.
 * @c: the UBIFS file-system description object
 * @lprops: LEB properties to test
 */
static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
{
	struct ubifs_pnode *pnode;
	int pos;

	pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1);
	pnode = (struct ubifs_pnode *)container_of(lprops - pos,
						   struct ubifs_pnode,
						   lprops[0]);
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	return !test_bit(COW_CNODE, &pnode->flags) &&
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	       test_bit(DIRTY_CNODE, &pnode->flags);
}

/**
 * ubifs_change_lp - change LEB properties.
 * @c: the UBIFS file-system description object
 * @lp: LEB properties to change
 * @free: new free space amount
 * @dirty: new dirty space amount
 * @flags: new flags
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 * @idx_gc_cnt: change to the count of @idx_gc list
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 *
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 * This function changes LEB properties (@free, @dirty or @flag). However, the
 * property which has the %LPROPS_NC value is not changed. Returns a pointer to
 * the updated LEB properties on success and a negative error code on failure.
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 *
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 * Note, the LEB properties may have had to be copied (due to COW) and
 * consequently the pointer returned may not be the same as the pointer
 * passed.
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 */
const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
					   const struct ubifs_lprops *lp,
					   int free, int dirty, int flags,
					   int idx_gc_cnt)
{
	/*
	 * This is the only function that is allowed to change lprops, so we
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	 * discard the "const" qualifier.
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	 */
	struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;

	dbg_lp("LEB %d, free %d, dirty %d, flags %d",
	       lprops->lnum, free, dirty, flags);

	ubifs_assert(mutex_is_locked(&c->lp_mutex));
	ubifs_assert(c->lst.empty_lebs >= 0 &&
		     c->lst.empty_lebs <= c->main_lebs);
	ubifs_assert(c->freeable_cnt >= 0);
	ubifs_assert(c->freeable_cnt <= c->main_lebs);
	ubifs_assert(c->lst.taken_empty_lebs >= 0);
	ubifs_assert(c->lst.taken_empty_lebs <= c->lst.empty_lebs);
	ubifs_assert(!(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
	ubifs_assert(!(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
	ubifs_assert(!(c->lst.total_used & 7));
	ubifs_assert(free == LPROPS_NC || free >= 0);
	ubifs_assert(dirty == LPROPS_NC || dirty >= 0);

	if (!is_lprops_dirty(c, lprops)) {
		lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum);
		if (IS_ERR(lprops))
			return lprops;
	} else
		ubifs_assert(lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));

	ubifs_assert(!(lprops->free & 7) && !(lprops->dirty & 7));

	spin_lock(&c->space_lock);
	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
		c->lst.taken_empty_lebs -= 1;

	if (!(lprops->flags & LPROPS_INDEX)) {
		int old_spc;

		old_spc = lprops->free + lprops->dirty;
		if (old_spc < c->dead_wm)
			c->lst.total_dead -= old_spc;
		else
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			c->lst.total_dark -= ubifs_calc_dark(c, old_spc);
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		c->lst.total_used -= c->leb_size - old_spc;
	}

	if (free != LPROPS_NC) {
		free = ALIGN(free, 8);
		c->lst.total_free += free - lprops->free;

		/* Increase or decrease empty LEBs counter if needed */
		if (free == c->leb_size) {
			if (lprops->free != c->leb_size)
				c->lst.empty_lebs += 1;
		} else if (lprops->free == c->leb_size)
			c->lst.empty_lebs -= 1;
		lprops->free = free;
	}

	if (dirty != LPROPS_NC) {
		dirty = ALIGN(dirty, 8);
		c->lst.total_dirty += dirty - lprops->dirty;
		lprops->dirty = dirty;
	}

	if (flags != LPROPS_NC) {
		/* Take care about indexing LEBs counter if needed */
		if ((lprops->flags & LPROPS_INDEX)) {
			if (!(flags & LPROPS_INDEX))
				c->lst.idx_lebs -= 1;
		} else if (flags & LPROPS_INDEX)
			c->lst.idx_lebs += 1;
		lprops->flags = flags;
	}

	if (!(lprops->flags & LPROPS_INDEX)) {
		int new_spc;

		new_spc = lprops->free + lprops->dirty;
		if (new_spc < c->dead_wm)
			c->lst.total_dead += new_spc;
		else
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			c->lst.total_dark += ubifs_calc_dark(c, new_spc);
623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640

		c->lst.total_used += c->leb_size - new_spc;
	}

	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
		c->lst.taken_empty_lebs += 1;

	change_category(c, lprops);
	c->idx_gc_cnt += idx_gc_cnt;
	spin_unlock(&c->space_lock);
	return lprops;
}

/**
 * ubifs_get_lp_stats - get lprops statistics.
 * @c: UBIFS file-system description object
 * @st: return statistics
 */
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));
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	spin_unlock(&c->space_lock);
}

/**
 * ubifs_change_one_lp - change LEB properties.
 * @c: the UBIFS file-system description object
 * @lnum: LEB to change properties for
 * @free: amount of free space
 * @dirty: amount of dirty space
 * @flags_set: flags to set
 * @flags_clean: flags to clean
 * @idx_gc_cnt: change to the count of idx_gc list
 *
 * This function changes properties of LEB @lnum. It is a helper wrapper over
 * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the
 * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and
 * a negative error code in case of failure.
 */
int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
			int flags_set, int flags_clean, int idx_gc_cnt)
{
	int err = 0, flags;
	const struct ubifs_lprops *lp;

	ubifs_get_lprops(c);

	lp = ubifs_lpt_lookup_dirty(c, lnum);
	if (IS_ERR(lp)) {
		err = PTR_ERR(lp);
		goto out;
	}

	flags = (lp->flags | flags_set) & ~flags_clean;
	lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt);
	if (IS_ERR(lp))
		err = PTR_ERR(lp);

out:
	ubifs_release_lprops(c);
684
	if (err)
685
		ubifs_err(c, "cannot change properties of LEB %d, error %d",
686
			  lnum, err);
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	return err;
}

/**
 * ubifs_update_one_lp - update LEB properties.
 * @c: the UBIFS file-system description object
 * @lnum: LEB to change properties for
 * @free: amount of free space
 * @dirty: amount of dirty space to add
 * @flags_set: flags to set
 * @flags_clean: flags to clean
 *
 * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to
 * current dirty space, not substitutes it.
 */
int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
			int flags_set, int flags_clean)
{
	int err = 0, flags;
	const struct ubifs_lprops *lp;

	ubifs_get_lprops(c);

	lp = ubifs_lpt_lookup_dirty(c, lnum);
	if (IS_ERR(lp)) {
		err = PTR_ERR(lp);
		goto out;
	}

	flags = (lp->flags | flags_set) & ~flags_clean;
	lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0);
	if (IS_ERR(lp))
		err = PTR_ERR(lp);

out:
	ubifs_release_lprops(c);
723
	if (err)
724
		ubifs_err(c, "cannot update properties of LEB %d, error %d",
725
			  lnum, err);
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	return err;
}

/**
 * ubifs_read_one_lp - read LEB properties.
 * @c: the UBIFS file-system description object
 * @lnum: LEB to read properties for
 * @lp: where to store read properties
 *
 * This helper function reads properties of a LEB @lnum and stores them in @lp.
 * Returns zero in case of success and a negative error code in case of
 * failure.
 */
int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp)
{
	int err = 0;
	const struct ubifs_lprops *lpp;

	ubifs_get_lprops(c);

	lpp = ubifs_lpt_lookup(c, lnum);
	if (IS_ERR(lpp)) {
		err = PTR_ERR(lpp);
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		ubifs_err(c, "cannot read properties of LEB %d, error %d",
750
			  lnum, err);
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		goto out;
	}

	memcpy(lp, lpp, sizeof(struct ubifs_lprops));

out:
	ubifs_release_lprops(c);
	return err;
}

/**
 * ubifs_fast_find_free - try to find a LEB with free space quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for a LEB with free space or %NULL if
 * the function is unable to find a LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;
	struct ubifs_lpt_heap *heap;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	heap = &c->lpt_heap[LPROPS_FREE - 1];
	if (heap->cnt == 0)
		return NULL;

	lprops = heap->arr[0];
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
	return lprops;
}

/**
 * ubifs_fast_find_empty - try to find an empty LEB quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for an empty LEB or %NULL if the
 * function is unable to find an empty LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	if (list_empty(&c->empty_list))
		return NULL;

	lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list);
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
	ubifs_assert(lprops->free == c->leb_size);
	return lprops;
}

/**
 * ubifs_fast_find_freeable - try to find a freeable LEB quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for a freeable LEB or %NULL if the
 * function is unable to find a freeable LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	if (list_empty(&c->freeable_list))
		return NULL;

	lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list);
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
	ubifs_assert(c->freeable_cnt > 0);
	return lprops;
}

/**
 * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly.
 * @c: the UBIFS file-system description object
 *
 * This function returns LEB properties for a freeable index LEB or %NULL if the
 * function is unable to find a freeable index LEB quickly.
 */
const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;

	ubifs_assert(mutex_is_locked(&c->lp_mutex));

	if (list_empty(&c->frdi_idx_list))
		return NULL;

	lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list);
	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
	ubifs_assert((lprops->flags & LPROPS_INDEX));
	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
	return lprops;
}

855 856 857
/*
 * Everything below is related to debugging.
 */
858 859 860 861 862 863 864 865 866 867 868 869 870

/**
 * dbg_check_cats - check category heaps and lists.
 * @c: UBIFS file-system description object
 *
 * This function returns %0 on success and a negative error code on failure.
 */
int dbg_check_cats(struct ubifs_info *c)
{
	struct ubifs_lprops *lprops;
	struct list_head *pos;
	int i, cat;

871
	if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
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		return 0;

	list_for_each_entry(lprops, &c->empty_list, list) {
		if (lprops->free != c->leb_size) {
876
			ubifs_err(c, "non-empty LEB %d on empty list (free %d dirty %d flags %d)",
877 878
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
879 880 881
			return -EINVAL;
		}
		if (lprops->flags & LPROPS_TAKEN) {
882
			ubifs_err(c, "taken LEB %d on empty list (free %d dirty %d flags %d)",
883 884
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
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			return -EINVAL;
		}
	}

	i = 0;
	list_for_each_entry(lprops, &c->freeable_list, list) {
		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)",
893 894
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
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			return -EINVAL;
		}
		if (lprops->flags & LPROPS_TAKEN) {
898
			ubifs_err(c, "taken LEB %d on freeable list (free %d dirty %d flags %d)",
899 900
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
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			return -EINVAL;
		}
		i += 1;
	}
	if (i != c->freeable_cnt) {
906
		ubifs_err(c, "freeable list count %d expected %d", i,
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			  c->freeable_cnt);
		return -EINVAL;
	}

	i = 0;
	list_for_each(pos, &c->idx_gc)
		i += 1;
	if (i != c->idx_gc_cnt) {
915
		ubifs_err(c, "idx_gc list count %d expected %d", i,
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			  c->idx_gc_cnt);
		return -EINVAL;
	}

	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
		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)",
923 924
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
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			return -EINVAL;
		}
		if (lprops->flags & LPROPS_TAKEN) {
928
			ubifs_err(c, "taken LEB %d on frdi_idx list (free %d dirty %d flags %d)",
929 930
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
931 932 933
			return -EINVAL;
		}
		if (!(lprops->flags & LPROPS_INDEX)) {
934
			ubifs_err(c, "non-index LEB %d on frdi_idx list (free %d dirty %d flags %d)",
935 936
				  lprops->lnum, lprops->free, lprops->dirty,
				  lprops->flags);
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			return -EINVAL;
		}
	}

	for (cat = 1; cat <= LPROPS_HEAP_CNT; cat++) {
		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];

		for (i = 0; i < heap->cnt; i++) {
			lprops = heap->arr[i];
			if (!lprops) {
947
				ubifs_err(c, "null ptr in LPT heap cat %d", cat);
948 949 950
				return -EINVAL;
			}
			if (lprops->hpos != i) {
951
				ubifs_err(c, "bad ptr in LPT heap cat %d", cat);
952 953 954
				return -EINVAL;
			}
			if (lprops->flags & LPROPS_TAKEN) {
955
				ubifs_err(c, "taken LEB in LPT heap cat %d", cat);
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				return -EINVAL;
			}
		}
	}

	return 0;
}

void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
		    int add_pos)
{
	int i = 0, j, err = 0;

969
	if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990
		return;

	for (i = 0; i < heap->cnt; i++) {
		struct ubifs_lprops *lprops = heap->arr[i];
		struct ubifs_lprops *lp;

		if (i != add_pos)
			if ((lprops->flags & LPROPS_CAT_MASK) != cat) {
				err = 1;
				goto out;
			}
		if (lprops->hpos != i) {
			err = 2;
			goto out;
		}
		lp = ubifs_lpt_lookup(c, lprops->lnum);
		if (IS_ERR(lp)) {
			err = 3;
			goto out;
		}
		if (lprops != lp) {
991
			ubifs_err(c, "lprops %zx lp %zx lprops->lnum %d lp->lnum %d",
Artem Bityutskiy's avatar
Artem Bityutskiy committed
992 993
				  (size_t)lprops, (size_t)lp, lprops->lnum,
				  lp->lnum);
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			err = 4;
			goto out;
		}
		for (j = 0; j < i; j++) {
			lp = heap->arr[j];
			if (lp == lprops) {
				err = 5;
				goto out;
			}
			if (lp->lnum == lprops->lnum) {
				err = 6;
				goto out;
			}
		}
	}
out:
	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 1019 1020 1021
	}
}

/**
 * scan_check_cb - scan callback.
 * @c: the UBIFS file-system description object
 * @lp: LEB properties to scan
 * @in_tree: whether the LEB properties are in main memory
1022
 * @lst: lprops statistics to update
1023 1024 1025 1026 1027 1028 1029 1030
 *
 * This function returns a code that indicates whether the scan should continue
 * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
 * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
 * (%LPT_SCAN_STOP).
 */
static int scan_check_cb(struct ubifs_info *c,
			 const struct ubifs_lprops *lp, int in_tree,
1031
			 struct ubifs_lp_stats *lst)
1032 1033 1034
{
	struct ubifs_scan_leb *sleb;
	struct ubifs_scan_node *snod;
1035 1036
	int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty, ret;
	void *buf = NULL;
1037 1038 1039 1040 1041

	cat = lp->flags & LPROPS_CAT_MASK;
	if (cat != LPROPS_UNCAT) {
		cat = ubifs_categorize_lprops(c, lp);
		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 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076
		}
	}

	/* Check lp is on its category list (if it has one) */
	if (in_tree) {
		struct list_head *list = NULL;

		switch (cat) {
		case LPROPS_EMPTY:
			list = &c->empty_list;
			break;
		case LPROPS_FREEABLE:
			list = &c->freeable_list;
			break;
		case LPROPS_FRDI_IDX:
			list = &c->frdi_idx_list;
			break;
		case LPROPS_UNCAT:
			list = &c->uncat_list;
			break;
		}
		if (list) {
			struct ubifs_lprops *lprops;
			int found = 0;

			list_for_each_entry(lprops, list, list) {
				if (lprops == lp) {
					found = 1;
					break;
				}
			}
			if (!found) {
1077
				ubifs_err(c, "bad LPT list (category %d)", cat);
1078
				return -EINVAL;
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			}
		}
	}

	/* Check lp is on its category heap (if it has one) */
	if (in_tree && cat > 0 && cat <= LPROPS_HEAP_CNT) {
		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];

		if ((lp->hpos != -1 && heap->arr[lp->hpos]->lnum != lnum) ||
		    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 1096
	if (!buf)
		return -ENOMEM;
1097

1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
	/*
	 * After an unclean unmount, empty and freeable LEBs
	 * may contain garbage - do not scan them.
	 */
	if (lp->free == c->leb_size) {
		lst->empty_lebs += 1;
		lst->total_free += c->leb_size;
		lst->total_dark += ubifs_calc_dark(c, c->leb_size);
		return LPT_SCAN_CONTINUE;
	}
	if (lp->free + lp->dirty == c->leb_size &&
	    !(lp->flags & LPROPS_INDEX)) {
		lst->total_free  += lp->free;
		lst->total_dirty += lp->dirty;
		lst->total_dark  +=  ubifs_calc_dark(c, c->leb_size);
		return LPT_SCAN_CONTINUE;
	}

1116
	sleb = ubifs_scan(c, lnum, 0, buf, 0);
1117
	if (IS_ERR(sleb)) {
1118
		ret = PTR_ERR(sleb);
1119
		if (ret == -EUCLEAN) {
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			ubifs_dump_lprops(c);
			ubifs_dump_budg(c, &c->bi);
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		}
1123
		goto out;
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	}

	is_idx = -1;
	list_for_each_entry(snod, &sleb->nodes, list) {
		int found, level = 0;

		cond_resched();

		if (is_idx == -1)
			is_idx = (snod->type == UBIFS_IDX_NODE) ? 1 : 0;

		if (is_idx && snod->type != UBIFS_IDX_NODE) {
1136
			ubifs_err(c, "indexing node in data LEB %d:%d",
1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
				  lnum, snod->offs);
			goto out_destroy;
		}

		if (snod->type == UBIFS_IDX_NODE) {
			struct ubifs_idx_node *idx = snod->node;

			key_read(c, ubifs_idx_key(c, idx), &snod->key);
			level = le16_to_cpu(idx->level);
		}

		found = ubifs_tnc_has_node(c, &snod->key, level, lnum,
					   snod->offs, is_idx);
		if (found) {
			if (found < 0)
				goto out_destroy;
			used += ALIGN(snod->len, 8);
		}
	}

	free = c->leb_size - sleb->endpt;
	dirty = sleb->endpt - used;

	if (free > c->leb_size || free < 0 || dirty > c->leb_size ||
	    dirty < 0) {
1162
		ubifs_err(c, "bad calculated accounting for LEB %d: free %d, dirty %d",
1163
			  lnum, free, dirty);
1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208
		goto out_destroy;
	}

	if (lp->free + lp->dirty == c->leb_size &&
	    free + dirty == c->leb_size)
		if ((is_idx && !(lp->flags & LPROPS_INDEX)) ||
		    (!is_idx && free == c->leb_size) ||
		    lp->free == c->leb_size) {
			/*
			 * Empty or freeable LEBs could contain index
			 * nodes from an uncompleted commit due to an
			 * unclean unmount. Or they could be empty for
			 * the same reason. Or it may simply not have been
			 * unmapped.
			 */
			free = lp->free;
			dirty = lp->dirty;
			is_idx = 0;
		    }

	if (is_idx && lp->free + lp->dirty == free + dirty &&
	    lnum != c->ihead_lnum) {
		/*
		 * After an unclean unmount, an index LEB could have a different
		 * amount of free space than the value recorded by lprops. That
		 * is because the in-the-gaps method may use free space or
		 * create free space (as a side-effect of using ubi_leb_change
		 * and not writing the whole LEB). The incorrect free space
		 * value is not a problem because the index is only ever
		 * allocated empty LEBs, so there will never be an attempt to
		 * write to the free space at the end of an index LEB - except
		 * by the in-the-gaps method for which it is not a problem.
		 */
		free = lp->free;
		dirty = lp->dirty;
	}

	if (lp->free != free || lp->dirty != dirty)
		goto out_print;

	if (is_idx && !(lp->flags & LPROPS_INDEX)) {
		if (free == c->leb_size)
			/* Free but not unmapped LEB, it's fine */
			is_idx = 0;
		else {
1209
			ubifs_err(c, "indexing node without indexing flag");
1210 1211 1212 1213 1214
			goto out_print;
		}
	}

	if (!is_idx && (lp->flags & LPROPS_INDEX)) {
1215
		ubifs_err(c, "data node with indexing flag");
1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235
		goto out_print;
	}

	if (free == c->leb_size)
		lst->empty_lebs += 1;

	if (is_idx)
		lst->idx_lebs += 1;

	if (!(lp->flags & LPROPS_INDEX))
		lst->total_used += c->leb_size - free - dirty;
	lst->total_free += free;
	lst->total_dirty += dirty;

	if (!(lp->flags & LPROPS_INDEX)) {
		int spc = free + dirty;

		if (spc < c->dead_wm)
			lst->total_dead += spc;
		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 1248
out_destroy:
	ubifs_scan_destroy(sleb);
1249
	ret = -EINVAL;
1250
out:
1251
	vfree(buf);
1252
	return ret;
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268
}

/**
 * dbg_check_lprops - check all LEB properties.
 * @c: UBIFS file-system description object
 *
 * This function checks all LEB properties and makes sure they are all correct.
 * It returns zero if everything is fine, %-EINVAL if there is an inconsistency
 * and other negative error codes in case of other errors. This function is
 * called while the file system is locked (because of commit start), so no
 * additional locking is required. Note that locking the LPT mutex would cause
 * a circular lock dependency with the TNC mutex.
 */
int dbg_check_lprops(struct ubifs_info *c)
{
	int i, err;
1269
	struct ubifs_lp_stats lst;
1270

1271
	if (!dbg_is_chk_lprops(c))
1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283
		return 0;

	/*
	 * As we are going to scan the media, the write buffers have to be
	 * synchronized.
	 */
	for (i = 0; i < c->jhead_cnt; i++) {
		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
		if (err)
			return err;
	}

1284
	memset(&lst, 0, sizeof(struct ubifs_lp_stats));
1285 1286
	err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
				    (ubifs_lpt_scan_callback)scan_check_cb,
1287
				    &lst);
1288 1289 1290
	if (err && err != -ENOSPC)
		goto out;

1291 1292 1293 1294 1295
	if (lst.empty_lebs != c->lst.empty_lebs ||
	    lst.idx_lebs != c->lst.idx_lebs ||
	    lst.total_free != c->lst.total_free ||
	    lst.total_dirty != c->lst.total_dirty ||
	    lst.total_used != c->lst.total_used) {
1296 1297
		ubifs_err(c, "bad overall accounting");
		ubifs_err(c, "calculated: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld",
1298 1299
			  lst.empty_lebs, lst.idx_lebs, lst.total_free,
			  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 1302 1303 1304 1305 1306
			  c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
			  c->lst.total_dirty, c->lst.total_used);
		err = -EINVAL;
		goto out;
	}

1307 1308
	if (lst.total_dead != c->lst.total_dead ||
	    lst.total_dark != c->lst.total_dark) {
1309 1310
		ubifs_err(c, "bad dead/dark space accounting");
		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 1314 1315 1316 1317 1318 1319 1320 1321
			  c->lst.total_dead, c->lst.total_dark);
		err = -EINVAL;
		goto out;
	}

	err = dbg_check_cats(c);
out:
	return err;
}