u-boot/fs/ubifs/lprops.c
Stefan Roese 9eefe2a2b3 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>
2009-03-20 22:39:15 +01:00

842 lines
24 KiB
C

/*
* 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;
}