Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1319 insertions, 0 deletions

diff --git a/fs/ubifs/lprops.c b/fs/ubifs/lprops.c
new file mode 100644
index 000000000..fa8d775c9
--- /dev/null
+++ b/fs/ubifs/lprops.c
@@ -0,0 +1,1319 @@
+/*
+ * 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 */
+			}
+		}
+	}
+
+	/* 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(c, cpos >= b);
+		ubifs_assert(c, cpos < LPT_HEAP_SZ);
+		ubifs_assert(c, 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(c, hpos >= 0 && hpos < heap->cnt);
+	ubifs_assert(c, 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
+ * @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 *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;
+		/* No more room on heap so make it un-categorized */
+		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(c, 0);
+	}
+
+	lprops->flags &= ~LPROPS_CAT_MASK;
+	lprops->flags |= cat;
+	c->in_a_category_cnt += 1;
+	ubifs_assert(c, c->in_a_category_cnt <= c->main_lebs);
+}
+
+/**
+ * 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, c->freeable_cnt >= 0);
+		/* Fall through */
+	case LPROPS_UNCAT:
+	case LPROPS_EMPTY:
+	case LPROPS_FRDI_IDX:
+		ubifs_assert(c, !list_empty(&lprops->list));
+		list_del(&lprops->list);
+		break;
+	default:
+		ubifs_assert(c, 0);
+	}
+
+	c->in_a_category_cnt -= 1;
+	ubifs_assert(c, c->in_a_category_cnt >= 0);
+}
+
+/**
+ * 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, 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(c, 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
+ * 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.
+ */
+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(c, !(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
+ * @lprops: LEB properties to re-categorize
+ *
+ * LEB properties are categorized to enable fast find operations. When the LEB
+ * properties change they must be re-categorized.
+ */
+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) {
+		struct ubifs_lpt_heap *heap;
+
+		/* 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);
+	}
+}
+
+/**
+ * ubifs_calc_dark - calculate LEB dark space size.
+ * @c: the UBIFS file-system description object
+ * @spc: amount of free and dirty space in the LEB
+ *
+ * This function calculates and returns amount of dark space in an LEB which
+ * has @spc bytes of free and dirty space.
+ *
+ * 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.
+ */
+int ubifs_calc_dark(const struct ubifs_info *c, int spc)
+{
+	ubifs_assert(c, !(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]);
+	return !test_bit(COW_CNODE, &pnode->flags) &&
+	       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
+ * @idx_gc_cnt: change to the count of @idx_gc list
+ *
+ * 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.
+ *
+ * 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.
+ */
+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
+	 * discard the "const" qualifier.
+	 */
+	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(c, mutex_is_locked(&c->lp_mutex));
+	ubifs_assert(c, c->lst.empty_lebs >= 0 &&
+		     c->lst.empty_lebs <= c->main_lebs);
+	ubifs_assert(c, c->freeable_cnt >= 0);
+	ubifs_assert(c, c->freeable_cnt <= c->main_lebs);
+	ubifs_assert(c, c->lst.taken_empty_lebs >= 0);
+	ubifs_assert(c, c->lst.taken_empty_lebs <= c->lst.empty_lebs);
+	ubifs_assert(c, !(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
+	ubifs_assert(c, !(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
+	ubifs_assert(c, !(c->lst.total_used & 7));
+	ubifs_assert(c, free == LPROPS_NC || free >= 0);
+	ubifs_assert(c, 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(c, lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));
+
+	ubifs_assert(c, !(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
+			c->lst.total_dark -= ubifs_calc_dark(c, old_spc);
+
+		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
+			c->lst.total_dark += ubifs_calc_dark(c, new_spc);
+
+		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
+ * @lst: return statistics
+ */
+void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst)
+{
+	spin_lock(&c->space_lock);
+	memcpy(lst, &c->lst, sizeof(struct ubifs_lp_stats));
+	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);
+	if (err)
+		ubifs_err(c, "cannot change properties of LEB %d, error %d",
+			  lnum, err);
+	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);
+	if (err)
+		ubifs_err(c, "cannot update properties of LEB %d, error %d",
+			  lnum, err);
+	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);
+		ubifs_err(c, "cannot read properties of LEB %d, error %d",
+			  lnum, err);
+		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(c, 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(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, !(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(c, 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(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, !(lprops->flags & LPROPS_INDEX));
+	ubifs_assert(c, 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(c, 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(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, !(lprops->flags & LPROPS_INDEX));
+	ubifs_assert(c, lprops->free + lprops->dirty == c->leb_size);
+	ubifs_assert(c, 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(c, 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(c, !(lprops->flags & LPROPS_TAKEN));
+	ubifs_assert(c, (lprops->flags & LPROPS_INDEX));
+	ubifs_assert(c, lprops->free + lprops->dirty == c->leb_size);
+	return lprops;
+}
+
+/*
+ * Everything below is related to debugging.
+ */
+
+/**
+ * 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;
+
+	if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
+		return 0;
+
+	list_for_each_entry(lprops, &c->empty_list, list) {
+		if (lprops->free != c->leb_size) {
+			ubifs_err(c, "non-empty LEB %d on empty list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			return -EINVAL;
+		}
+		if (lprops->flags & LPROPS_TAKEN) {
+			ubifs_err(c, "taken LEB %d on empty list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			return -EINVAL;
+		}
+	}
+
+	i = 0;
+	list_for_each_entry(lprops, &c->freeable_list, list) {
+		if (lprops->free + lprops->dirty != c->leb_size) {
+			ubifs_err(c, "non-freeable LEB %d on freeable list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			return -EINVAL;
+		}
+		if (lprops->flags & LPROPS_TAKEN) {
+			ubifs_err(c, "taken LEB %d on freeable list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			return -EINVAL;
+		}
+		i += 1;
+	}
+	if (i != c->freeable_cnt) {
+		ubifs_err(c, "freeable list count %d expected %d", i,
+			  c->freeable_cnt);
+		return -EINVAL;
+	}
+
+	i = 0;
+	list_for_each(pos, &c->idx_gc)
+		i += 1;
+	if (i != c->idx_gc_cnt) {
+		ubifs_err(c, "idx_gc list count %d expected %d", i,
+			  c->idx_gc_cnt);
+		return -EINVAL;
+	}
+
+	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
+		if (lprops->free + lprops->dirty != c->leb_size) {
+			ubifs_err(c, "non-freeable LEB %d on frdi_idx list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			return -EINVAL;
+		}
+		if (lprops->flags & LPROPS_TAKEN) {
+			ubifs_err(c, "taken LEB %d on frdi_idx list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			return -EINVAL;
+		}
+		if (!(lprops->flags & LPROPS_INDEX)) {
+			ubifs_err(c, "non-index LEB %d on frdi_idx list (free %d dirty %d flags %d)",
+				  lprops->lnum, lprops->free, lprops->dirty,
+				  lprops->flags);
+			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) {
+				ubifs_err(c, "null ptr in LPT heap cat %d", cat);
+				return -EINVAL;
+			}
+			if (lprops->hpos != i) {
+				ubifs_err(c, "bad ptr in LPT heap cat %d", cat);
+				return -EINVAL;
+			}
+			if (lprops->flags & LPROPS_TAKEN) {
+				ubifs_err(c, "taken LEB in LPT heap cat %d", cat);
+				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;
+
+	if (!dbg_is_chk_gen(c) && !dbg_is_chk_lprops(c))
+		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) {
+			ubifs_err(c, "lprops %zx lp %zx lprops->lnum %d lp->lnum %d",
+				  (size_t)lprops, (size_t)lp, lprops->lnum,
+				  lp->lnum);
+			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) {
+		ubifs_err(c, "failed cat %d hpos %d err %d", cat, i, err);
+		dump_stack();
+		ubifs_dump_heap(c, heap, cat);
+	}
+}
+
+/**
+ * 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
+ * @lst: lprops statistics to update
+ *
+ * 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,
+			 struct ubifs_lp_stats *lst)
+{
+	struct ubifs_scan_leb *sleb;
+	struct ubifs_scan_node *snod;
+	int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty, ret;
+	void *buf = NULL;
+
+	cat = lp->flags & LPROPS_CAT_MASK;
+	if (cat != LPROPS_UNCAT) {
+		cat = ubifs_categorize_lprops(c, lp);
+		if (cat != (lp->flags & LPROPS_CAT_MASK)) {
+			ubifs_err(c, "bad LEB category %d expected %d",
+				  (lp->flags & LPROPS_CAT_MASK), cat);
+			return -EINVAL;
+		}
+	}
+
+	/* 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) {
+				ubifs_err(c, "bad LPT list (category %d)", cat);
+				return -EINVAL;
+			}
+		}
+	}
+
+	/* 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]) {
+			ubifs_err(c, "bad LPT heap (category %d)", cat);
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * 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;
+	}
+
+	buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	sleb = ubifs_scan(c, lnum, 0, buf, 0);
+	if (IS_ERR(sleb)) {
+		ret = PTR_ERR(sleb);
+		if (ret == -EUCLEAN) {
+			ubifs_dump_lprops(c);
+			ubifs_dump_budg(c, &c->bi);
+		}
+		goto out;
+	}
+
+	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) {
+			ubifs_err(c, "indexing node in data LEB %d:%d",
+				  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) {
+		ubifs_err(c, "bad calculated accounting for LEB %d: free %d, dirty %d",
+			  lnum, free, dirty);
+		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 {
+			ubifs_err(c, "indexing node without indexing flag");
+			goto out_print;
+		}
+	}
+
+	if (!is_idx && (lp->flags & LPROPS_INDEX)) {
+		ubifs_err(c, "data node with indexing flag");
+		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
+			lst->total_dark += ubifs_calc_dark(c, spc);
+	}
+
+	ubifs_scan_destroy(sleb);
+	vfree(buf);
+	return LPT_SCAN_CONTINUE;
+
+out_print:
+	ubifs_err(c, "bad accounting of LEB %d: free %d, dirty %d flags %#x, should be free %d, dirty %d",
+		  lnum, lp->free, lp->dirty, lp->flags, free, dirty);
+	ubifs_dump_leb(c, lnum);
+out_destroy:
+	ubifs_scan_destroy(sleb);
+	ret = -EINVAL;
+out:
+	vfree(buf);
+	return ret;
+}
+
+/**
+ * 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;
+	struct ubifs_lp_stats lst;
+
+	if (!dbg_is_chk_lprops(c))
+		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;
+	}
+
+	memset(&lst, 0, sizeof(struct ubifs_lp_stats));
+	err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
+				    (ubifs_lpt_scan_callback)scan_check_cb,
+				    &lst);
+	if (err && err != -ENOSPC)
+		goto out;
+
+	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) {
+		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",
+			  lst.empty_lebs, lst.idx_lebs, lst.total_free,
+			  lst.total_dirty, lst.total_used);
+		ubifs_err(c, "read from lprops: empty_lebs %d, idx_lebs %d, total_free %lld, total_dirty %lld, total_used %lld",
+			  c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
+			  c->lst.total_dirty, c->lst.total_used);
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (lst.total_dead != c->lst.total_dead ||
+	    lst.total_dark != c->lst.total_dark) {
+		ubifs_err(c, "bad dead/dark space accounting");
+		ubifs_err(c, "calculated: total_dead %lld, total_dark %lld",
+			  lst.total_dead, lst.total_dark);
+		ubifs_err(c, "read from lprops: total_dead %lld, total_dark %lld",
+			  c->lst.total_dead, c->lst.total_dark);
+		err = -EINVAL;
+		goto out;
+	}
+
+	err = dbg_check_cats(c);
+out:
+	return err;
+}