/*
* 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 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(0);
}
lprops->flags &= ~LPROPS_CAT_MASK;
lprops->flags |= cat;
c->in_a_category_cnt += 1;
ubifs_assert(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->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);
}
c->in_a_category_cnt -= 1;
ubifs_assert(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, 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
* 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(!(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(!(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(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 -= 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
* @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);
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(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;
}
/*
* 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;
}
}
buf = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
if (!buf)
return -ENOMEM;
/*
* 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;
}
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;
}
