UBIFS: Implement read-only UBIFS support in U-Boot
The U-Boot UBIFS implementation is largely a direct copy from the current
Linux version (2.6.29-rc6). As already done in the UBI version we have an
"abstraction layer" to redefine or remove some OS calls (e.g. mutex_lock()
...). This makes it possible to use the original Linux code with very
little changes. And by this we can better update to later Linux versions.
I removed some of the Linux features that are not used in the U-Boot
version (e.g. garbage-collection, write support).
Signed-off-by: Stefan Roese <sr@denx.de>
CC: Artem Bityutskiy <dedekind@infradead.org>
CC: Adrian Hunter <ext-Adrian.Hunter@nokia.com>
diff --git a/fs/ubifs/lprops.c b/fs/ubifs/lprops.c
new file mode 100644
index 0000000..8ce4949
--- /dev/null
+++ b/fs/ubifs/lprops.c
@@ -0,0 +1,842 @@
+/*
+ * 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(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;
+ /* No more room on heap so make it uncategorized */
+ 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);
+ }
+ lprops->flags &= ~LPROPS_CAT_MASK;
+ lprops->flags |= cat;
+}
+
+/**
+ * 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);
+ }
+}
+
+/**
+ * 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
+ * uncategorized 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(!(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 recategorize
+ *
+ * LEB properties are categorized to enable fast find operations. When the LEB
+ * properties change they must be recategorized.
+ */
+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 = &c->lpt_heap[new_cat - 1];
+
+ /* 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);
+ }
+}
+
+/**
+ * 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 amount of dark space in an LEB which has @spc bytes
+ * of free and dirty space. Returns the calculations result.
+ *
+ * Dark space is the space which is not always usable - it depends on which
+ * nodes are written in which order. E.g., if an LEB has only 512 free bytes,
+ * it is dark space, because it cannot fit a large data node. So UBIFS cannot
+ * count on this LEB and treat these 512 bytes as usable because it is not true
+ * if, for example, only big chunks of uncompressible data will be written to
+ * the FS.
+ */
+static int calc_dark(struct ubifs_info *c, int spc)
+{
+ 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]);
+ return !test_bit(COW_ZNODE, &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(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
+ c->lst.total_dark -= 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 += 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
+ * @st: 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);
+ 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);
+ 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);
+ 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;
+}