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![Artem Bityutskiy](/assets/img/avatar_default.png)
Make 'ubifs_find_free_space()' return offset where free space starts, rather than the amount of free space. This is just more appropriat for its caller. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
977 lines
30 KiB
C
977 lines
30 KiB
C
/*
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* This file is part of UBIFS.
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*
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* Copyright (C) 2006-2008 Nokia Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Authors: Artem Bityutskiy (Битюцкий Артём)
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* Adrian Hunter
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*/
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/*
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* This file contains functions for finding LEBs for various purposes e.g.
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* garbage collection. In general, lprops category heaps and lists are used
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* for fast access, falling back on scanning the LPT as a last resort.
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*/
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#include <linux/sort.h>
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#include "ubifs.h"
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/**
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* struct scan_data - data provided to scan callback functions
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* @min_space: minimum number of bytes for which to scan
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* @pick_free: whether it is OK to scan for empty LEBs
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* @lnum: LEB number found is returned here
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* @exclude_index: whether to exclude index LEBs
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*/
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struct scan_data {
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int min_space;
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int pick_free;
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int lnum;
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int exclude_index;
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};
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/**
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* valuable - determine whether LEB properties are valuable.
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* @c: the UBIFS file-system description object
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* @lprops: LEB properties
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*
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* This function return %1 if the LEB properties should be added to the LEB
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* properties tree in memory. Otherwise %0 is returned.
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*/
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static int valuable(struct ubifs_info *c, const struct ubifs_lprops *lprops)
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{
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int n, cat = lprops->flags & LPROPS_CAT_MASK;
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struct ubifs_lpt_heap *heap;
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switch (cat) {
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case LPROPS_DIRTY:
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case LPROPS_DIRTY_IDX:
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case LPROPS_FREE:
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heap = &c->lpt_heap[cat - 1];
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if (heap->cnt < heap->max_cnt)
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return 1;
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if (lprops->free + lprops->dirty >= c->dark_wm)
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return 1;
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return 0;
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case LPROPS_EMPTY:
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n = c->lst.empty_lebs + c->freeable_cnt -
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c->lst.taken_empty_lebs;
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if (n < c->lsave_cnt)
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return 1;
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return 0;
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case LPROPS_FREEABLE:
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return 1;
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case LPROPS_FRDI_IDX:
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return 1;
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}
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return 0;
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}
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/**
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* scan_for_dirty_cb - dirty space scan callback.
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* @c: the UBIFS file-system description object
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* @lprops: LEB properties to scan
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* @in_tree: whether the LEB properties are in main memory
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* @data: information passed to and from the caller of the scan
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*
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* This function returns a code that indicates whether the scan should continue
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* (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
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* in main memory (%LPT_SCAN_ADD), or whether the scan should stop
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* (%LPT_SCAN_STOP).
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*/
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static int scan_for_dirty_cb(struct ubifs_info *c,
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const struct ubifs_lprops *lprops, int in_tree,
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struct scan_data *data)
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{
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int ret = LPT_SCAN_CONTINUE;
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/* Exclude LEBs that are currently in use */
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if (lprops->flags & LPROPS_TAKEN)
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return LPT_SCAN_CONTINUE;
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/* Determine whether to add these LEB properties to the tree */
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if (!in_tree && valuable(c, lprops))
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ret |= LPT_SCAN_ADD;
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/* Exclude LEBs with too little space */
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if (lprops->free + lprops->dirty < data->min_space)
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return ret;
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/* If specified, exclude index LEBs */
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if (data->exclude_index && lprops->flags & LPROPS_INDEX)
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return ret;
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/* If specified, exclude empty or freeable LEBs */
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if (lprops->free + lprops->dirty == c->leb_size) {
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if (!data->pick_free)
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return ret;
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/* Exclude LEBs with too little dirty space (unless it is empty) */
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} else if (lprops->dirty < c->dead_wm)
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return ret;
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/* Finally we found space */
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data->lnum = lprops->lnum;
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return LPT_SCAN_ADD | LPT_SCAN_STOP;
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}
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/**
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* scan_for_dirty - find a data LEB with free space.
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* @c: the UBIFS file-system description object
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* @min_space: minimum amount free plus dirty space the returned LEB has to
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* have
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* @pick_free: if it is OK to return a free or freeable LEB
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* @exclude_index: whether to exclude index LEBs
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*
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* This function returns a pointer to the LEB properties found or a negative
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* error code.
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*/
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static const struct ubifs_lprops *scan_for_dirty(struct ubifs_info *c,
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int min_space, int pick_free,
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int exclude_index)
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{
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const struct ubifs_lprops *lprops;
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struct ubifs_lpt_heap *heap;
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struct scan_data data;
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int err, i;
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/* There may be an LEB with enough dirty space on the free heap */
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heap = &c->lpt_heap[LPROPS_FREE - 1];
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for (i = 0; i < heap->cnt; i++) {
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lprops = heap->arr[i];
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if (lprops->free + lprops->dirty < min_space)
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continue;
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if (lprops->dirty < c->dead_wm)
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continue;
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return lprops;
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}
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/*
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* A LEB may have fallen off of the bottom of the dirty heap, and ended
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* up as uncategorized even though it has enough dirty space for us now,
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* so check the uncategorized list. N.B. neither empty nor freeable LEBs
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* can end up as uncategorized because they are kept on lists not
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* finite-sized heaps.
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*/
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list_for_each_entry(lprops, &c->uncat_list, list) {
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if (lprops->flags & LPROPS_TAKEN)
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continue;
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if (lprops->free + lprops->dirty < min_space)
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continue;
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if (exclude_index && (lprops->flags & LPROPS_INDEX))
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continue;
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if (lprops->dirty < c->dead_wm)
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continue;
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return lprops;
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}
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/* We have looked everywhere in main memory, now scan the flash */
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if (c->pnodes_have >= c->pnode_cnt)
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/* All pnodes are in memory, so skip scan */
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return ERR_PTR(-ENOSPC);
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data.min_space = min_space;
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data.pick_free = pick_free;
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data.lnum = -1;
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data.exclude_index = exclude_index;
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err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
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(ubifs_lpt_scan_callback)scan_for_dirty_cb,
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&data);
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if (err)
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return ERR_PTR(err);
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ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
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c->lscan_lnum = data.lnum;
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lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
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if (IS_ERR(lprops))
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return lprops;
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ubifs_assert(lprops->lnum == data.lnum);
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ubifs_assert(lprops->free + lprops->dirty >= min_space);
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ubifs_assert(lprops->dirty >= c->dead_wm ||
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(pick_free &&
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lprops->free + lprops->dirty == c->leb_size));
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ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
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ubifs_assert(!exclude_index || !(lprops->flags & LPROPS_INDEX));
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return lprops;
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}
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/**
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* ubifs_find_dirty_leb - find a dirty LEB for the Garbage Collector.
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* @c: the UBIFS file-system description object
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* @ret_lp: LEB properties are returned here on exit
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* @min_space: minimum amount free plus dirty space the returned LEB has to
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* have
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* @pick_free: controls whether it is OK to pick empty or index LEBs
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*
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* This function tries to find a dirty logical eraseblock which has at least
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* @min_space free and dirty space. It prefers to take an LEB from the dirty or
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* dirty index heap, and it falls-back to LPT scanning if the heaps are empty
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* or do not have an LEB which satisfies the @min_space criteria.
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*
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* Note, LEBs which have less than dead watermark of free + dirty space are
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* never picked by this function.
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*
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* The additional @pick_free argument controls if this function has to return a
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* free or freeable LEB if one is present. For example, GC must to set it to %1,
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* when called from the journal space reservation function, because the
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* appearance of free space may coincide with the loss of enough dirty space
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* for GC to succeed anyway.
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*
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* In contrast, if the Garbage Collector is called from budgeting, it should
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* just make free space, not return LEBs which are already free or freeable.
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*
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* In addition @pick_free is set to %2 by the recovery process in order to
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* recover gc_lnum in which case an index LEB must not be returned.
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*
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* This function returns zero and the LEB properties of found dirty LEB in case
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* of success, %-ENOSPC if no dirty LEB was found and a negative error code in
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* case of other failures. The returned LEB is marked as "taken".
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*/
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int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
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int min_space, int pick_free)
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{
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int err = 0, sum, exclude_index = pick_free == 2 ? 1 : 0;
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const struct ubifs_lprops *lp = NULL, *idx_lp = NULL;
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struct ubifs_lpt_heap *heap, *idx_heap;
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ubifs_get_lprops(c);
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if (pick_free) {
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int lebs, rsvd_idx_lebs = 0;
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spin_lock(&c->space_lock);
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lebs = c->lst.empty_lebs + c->idx_gc_cnt;
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lebs += c->freeable_cnt - c->lst.taken_empty_lebs;
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/*
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* Note, the index may consume more LEBs than have been reserved
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* for it. It is OK because it might be consolidated by GC.
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* But if the index takes fewer LEBs than it is reserved for it,
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* this function must avoid picking those reserved LEBs.
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*/
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if (c->min_idx_lebs >= c->lst.idx_lebs) {
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rsvd_idx_lebs = c->min_idx_lebs - c->lst.idx_lebs;
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exclude_index = 1;
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}
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spin_unlock(&c->space_lock);
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/* Check if there are enough free LEBs for the index */
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if (rsvd_idx_lebs < lebs) {
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/* OK, try to find an empty LEB */
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lp = ubifs_fast_find_empty(c);
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if (lp)
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goto found;
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/* Or a freeable LEB */
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lp = ubifs_fast_find_freeable(c);
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if (lp)
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goto found;
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} else
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/*
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* We cannot pick free/freeable LEBs in the below code.
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*/
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pick_free = 0;
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} else {
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spin_lock(&c->space_lock);
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exclude_index = (c->min_idx_lebs >= c->lst.idx_lebs);
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spin_unlock(&c->space_lock);
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}
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/* Look on the dirty and dirty index heaps */
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heap = &c->lpt_heap[LPROPS_DIRTY - 1];
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idx_heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
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if (idx_heap->cnt && !exclude_index) {
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idx_lp = idx_heap->arr[0];
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sum = idx_lp->free + idx_lp->dirty;
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/*
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* Since we reserve thrice as much space for the index than it
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* actually takes, it does not make sense to pick indexing LEBs
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* with less than, say, half LEB of dirty space. May be half is
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* not the optimal boundary - this should be tested and
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* checked. This boundary should determine how much we use
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* in-the-gaps to consolidate the index comparing to how much
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* we use garbage collector to consolidate it. The "half"
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* criteria just feels to be fine.
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*/
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if (sum < min_space || sum < c->half_leb_size)
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idx_lp = NULL;
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}
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if (heap->cnt) {
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lp = heap->arr[0];
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if (lp->dirty + lp->free < min_space)
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lp = NULL;
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}
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/* Pick the LEB with most space */
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if (idx_lp && lp) {
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if (idx_lp->free + idx_lp->dirty >= lp->free + lp->dirty)
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lp = idx_lp;
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} else if (idx_lp && !lp)
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lp = idx_lp;
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if (lp) {
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ubifs_assert(lp->free + lp->dirty >= c->dead_wm);
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goto found;
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}
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/* Did not find a dirty LEB on the dirty heaps, have to scan */
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dbg_find("scanning LPT for a dirty LEB");
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lp = scan_for_dirty(c, min_space, pick_free, exclude_index);
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if (IS_ERR(lp)) {
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err = PTR_ERR(lp);
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goto out;
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}
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ubifs_assert(lp->dirty >= c->dead_wm ||
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(pick_free && lp->free + lp->dirty == c->leb_size));
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found:
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dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
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lp->lnum, lp->free, lp->dirty, lp->flags);
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lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
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lp->flags | LPROPS_TAKEN, 0);
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if (IS_ERR(lp)) {
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err = PTR_ERR(lp);
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goto out;
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}
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memcpy(ret_lp, lp, sizeof(struct ubifs_lprops));
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out:
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ubifs_release_lprops(c);
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return err;
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}
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/**
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* scan_for_free_cb - free space scan callback.
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* @c: the UBIFS file-system description object
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* @lprops: LEB properties to scan
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* @in_tree: whether the LEB properties are in main memory
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* @data: information passed to and from the caller of the scan
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*
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* This function returns a code that indicates whether the scan should continue
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* (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
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* in main memory (%LPT_SCAN_ADD), or whether the scan should stop
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* (%LPT_SCAN_STOP).
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*/
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static int scan_for_free_cb(struct ubifs_info *c,
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const struct ubifs_lprops *lprops, int in_tree,
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struct scan_data *data)
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{
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int ret = LPT_SCAN_CONTINUE;
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/* Exclude LEBs that are currently in use */
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if (lprops->flags & LPROPS_TAKEN)
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return LPT_SCAN_CONTINUE;
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/* Determine whether to add these LEB properties to the tree */
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if (!in_tree && valuable(c, lprops))
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ret |= LPT_SCAN_ADD;
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/* Exclude index LEBs */
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if (lprops->flags & LPROPS_INDEX)
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return ret;
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/* Exclude LEBs with too little space */
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if (lprops->free < data->min_space)
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return ret;
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/* If specified, exclude empty LEBs */
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if (!data->pick_free && lprops->free == c->leb_size)
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return ret;
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/*
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* LEBs that have only free and dirty space must not be allocated
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* because they may have been unmapped already or they may have data
|
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* that is obsolete only because of nodes that are still sitting in a
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* wbuf.
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*/
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if (lprops->free + lprops->dirty == c->leb_size && lprops->dirty > 0)
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return ret;
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/* Finally we found space */
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data->lnum = lprops->lnum;
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return LPT_SCAN_ADD | LPT_SCAN_STOP;
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}
|
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|
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/**
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* do_find_free_space - find a data LEB with free space.
|
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* @c: the UBIFS file-system description object
|
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* @min_space: minimum amount of free space required
|
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* @pick_free: whether it is OK to scan for empty LEBs
|
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* @squeeze: whether to try to find space in a non-empty LEB first
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*
|
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* This function returns a pointer to the LEB properties found or a negative
|
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* error code.
|
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*/
|
|
static
|
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const struct ubifs_lprops *do_find_free_space(struct ubifs_info *c,
|
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int min_space, int pick_free,
|
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int squeeze)
|
|
{
|
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const struct ubifs_lprops *lprops;
|
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struct ubifs_lpt_heap *heap;
|
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struct scan_data data;
|
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int err, i;
|
|
|
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if (squeeze) {
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lprops = ubifs_fast_find_free(c);
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if (lprops && lprops->free >= min_space)
|
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return lprops;
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}
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if (pick_free) {
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lprops = ubifs_fast_find_empty(c);
|
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if (lprops)
|
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return lprops;
|
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}
|
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if (!squeeze) {
|
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lprops = ubifs_fast_find_free(c);
|
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if (lprops && lprops->free >= min_space)
|
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return lprops;
|
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}
|
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/* There may be an LEB with enough free space on the dirty heap */
|
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heap = &c->lpt_heap[LPROPS_DIRTY - 1];
|
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for (i = 0; i < heap->cnt; i++) {
|
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lprops = heap->arr[i];
|
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if (lprops->free >= min_space)
|
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return lprops;
|
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}
|
|
/*
|
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* A LEB may have fallen off of the bottom of the free heap, and ended
|
|
* up as uncategorized even though it has enough free space for us now,
|
|
* so check the uncategorized list. N.B. neither empty nor freeable LEBs
|
|
* can end up as uncategorized because they are kept on lists not
|
|
* finite-sized heaps.
|
|
*/
|
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list_for_each_entry(lprops, &c->uncat_list, list) {
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if (lprops->flags & LPROPS_TAKEN)
|
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continue;
|
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if (lprops->flags & LPROPS_INDEX)
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continue;
|
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if (lprops->free >= min_space)
|
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return lprops;
|
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}
|
|
/* We have looked everywhere in main memory, now scan the flash */
|
|
if (c->pnodes_have >= c->pnode_cnt)
|
|
/* All pnodes are in memory, so skip scan */
|
|
return ERR_PTR(-ENOSPC);
|
|
data.min_space = min_space;
|
|
data.pick_free = pick_free;
|
|
data.lnum = -1;
|
|
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
|
|
(ubifs_lpt_scan_callback)scan_for_free_cb,
|
|
&data);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
|
|
c->lscan_lnum = data.lnum;
|
|
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
|
|
if (IS_ERR(lprops))
|
|
return lprops;
|
|
ubifs_assert(lprops->lnum == data.lnum);
|
|
ubifs_assert(lprops->free >= min_space);
|
|
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
|
|
ubifs_assert(!(lprops->flags & LPROPS_INDEX));
|
|
return lprops;
|
|
}
|
|
|
|
/**
|
|
* ubifs_find_free_space - find a data LEB with free space.
|
|
* @c: the UBIFS file-system description object
|
|
* @min_space: minimum amount of required free space
|
|
* @offs: contains offset of where free space starts on exit
|
|
* @squeeze: whether to try to find space in a non-empty LEB first
|
|
*
|
|
* This function looks for an LEB with at least @min_space bytes of free space.
|
|
* It tries to find an empty LEB if possible. If no empty LEBs are available,
|
|
* this function searches for a non-empty data LEB. The returned LEB is marked
|
|
* as "taken".
|
|
*
|
|
* This function returns found LEB number in case of success, %-ENOSPC if it
|
|
* failed to find a LEB with @min_space bytes of free space and other a negative
|
|
* error codes in case of failure.
|
|
*/
|
|
int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *offs,
|
|
int squeeze)
|
|
{
|
|
const struct ubifs_lprops *lprops;
|
|
int lebs, rsvd_idx_lebs, pick_free = 0, err, lnum, flags;
|
|
|
|
dbg_find("min_space %d", min_space);
|
|
ubifs_get_lprops(c);
|
|
|
|
/* Check if there are enough empty LEBs for commit */
|
|
spin_lock(&c->space_lock);
|
|
if (c->min_idx_lebs > c->lst.idx_lebs)
|
|
rsvd_idx_lebs = c->min_idx_lebs - c->lst.idx_lebs;
|
|
else
|
|
rsvd_idx_lebs = 0;
|
|
lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
|
|
c->lst.taken_empty_lebs;
|
|
if (rsvd_idx_lebs < lebs)
|
|
/*
|
|
* OK to allocate an empty LEB, but we still don't want to go
|
|
* looking for one if there aren't any.
|
|
*/
|
|
if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
|
|
pick_free = 1;
|
|
/*
|
|
* Because we release the space lock, we must account
|
|
* for this allocation here. After the LEB properties
|
|
* flags have been updated, we subtract one. Note, the
|
|
* result of this is that lprops also decreases
|
|
* @taken_empty_lebs in 'ubifs_change_lp()', so it is
|
|
* off by one for a short period of time which may
|
|
* introduce a small disturbance to budgeting
|
|
* calculations, but this is harmless because at the
|
|
* worst case this would make the budgeting subsystem
|
|
* be more pessimistic than needed.
|
|
*
|
|
* Fundamentally, this is about serialization of the
|
|
* budgeting and lprops subsystems. We could make the
|
|
* @space_lock a mutex and avoid dropping it before
|
|
* calling 'ubifs_change_lp()', but mutex is more
|
|
* heavy-weight, and we want budgeting to be as fast as
|
|
* possible.
|
|
*/
|
|
c->lst.taken_empty_lebs += 1;
|
|
}
|
|
spin_unlock(&c->space_lock);
|
|
|
|
lprops = do_find_free_space(c, min_space, pick_free, squeeze);
|
|
if (IS_ERR(lprops)) {
|
|
err = PTR_ERR(lprops);
|
|
goto out;
|
|
}
|
|
|
|
lnum = lprops->lnum;
|
|
flags = lprops->flags | LPROPS_TAKEN;
|
|
|
|
lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC, flags, 0);
|
|
if (IS_ERR(lprops)) {
|
|
err = PTR_ERR(lprops);
|
|
goto out;
|
|
}
|
|
|
|
if (pick_free) {
|
|
spin_lock(&c->space_lock);
|
|
c->lst.taken_empty_lebs -= 1;
|
|
spin_unlock(&c->space_lock);
|
|
}
|
|
|
|
*offs = c->leb_size - lprops->free;
|
|
ubifs_release_lprops(c);
|
|
|
|
if (*offs == 0) {
|
|
/*
|
|
* Ensure that empty LEBs have been unmapped. They may not have
|
|
* been, for example, because of an unclean unmount. Also
|
|
* LEBs that were freeable LEBs (free + dirty == leb_size) will
|
|
* not have been unmapped.
|
|
*/
|
|
err = ubifs_leb_unmap(c, lnum);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
dbg_find("found LEB %d, free %d", lnum, c->leb_size - *offs);
|
|
ubifs_assert(*offs <= c->leb_size - min_space);
|
|
return lnum;
|
|
|
|
out:
|
|
if (pick_free) {
|
|
spin_lock(&c->space_lock);
|
|
c->lst.taken_empty_lebs -= 1;
|
|
spin_unlock(&c->space_lock);
|
|
}
|
|
ubifs_release_lprops(c);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* scan_for_idx_cb - callback used by the scan for a free LEB for the index.
|
|
* @c: the UBIFS file-system description object
|
|
* @lprops: LEB properties to scan
|
|
* @in_tree: whether the LEB properties are in main memory
|
|
* @data: information passed to and from the caller of the scan
|
|
*
|
|
* 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_for_idx_cb(struct ubifs_info *c,
|
|
const struct ubifs_lprops *lprops, int in_tree,
|
|
struct scan_data *data)
|
|
{
|
|
int ret = LPT_SCAN_CONTINUE;
|
|
|
|
/* Exclude LEBs that are currently in use */
|
|
if (lprops->flags & LPROPS_TAKEN)
|
|
return LPT_SCAN_CONTINUE;
|
|
/* Determine whether to add these LEB properties to the tree */
|
|
if (!in_tree && valuable(c, lprops))
|
|
ret |= LPT_SCAN_ADD;
|
|
/* Exclude index LEBS */
|
|
if (lprops->flags & LPROPS_INDEX)
|
|
return ret;
|
|
/* Exclude LEBs that cannot be made empty */
|
|
if (lprops->free + lprops->dirty != c->leb_size)
|
|
return ret;
|
|
/*
|
|
* We are allocating for the index so it is safe to allocate LEBs with
|
|
* only free and dirty space, because write buffers are sync'd at commit
|
|
* start.
|
|
*/
|
|
data->lnum = lprops->lnum;
|
|
return LPT_SCAN_ADD | LPT_SCAN_STOP;
|
|
}
|
|
|
|
/**
|
|
* scan_for_leb_for_idx - scan for a free LEB for the index.
|
|
* @c: the UBIFS file-system description object
|
|
*/
|
|
static const struct ubifs_lprops *scan_for_leb_for_idx(struct ubifs_info *c)
|
|
{
|
|
struct ubifs_lprops *lprops;
|
|
struct scan_data data;
|
|
int err;
|
|
|
|
data.lnum = -1;
|
|
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
|
|
(ubifs_lpt_scan_callback)scan_for_idx_cb,
|
|
&data);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
|
|
c->lscan_lnum = data.lnum;
|
|
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
|
|
if (IS_ERR(lprops))
|
|
return lprops;
|
|
ubifs_assert(lprops->lnum == data.lnum);
|
|
ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
|
|
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
|
|
ubifs_assert(!(lprops->flags & LPROPS_INDEX));
|
|
return lprops;
|
|
}
|
|
|
|
/**
|
|
* ubifs_find_free_leb_for_idx - find a free LEB for the index.
|
|
* @c: the UBIFS file-system description object
|
|
*
|
|
* This function looks for a free LEB and returns that LEB number. The returned
|
|
* LEB is marked as "taken", "index".
|
|
*
|
|
* Only empty LEBs are allocated. This is for two reasons. First, the commit
|
|
* calculates the number of LEBs to allocate based on the assumption that they
|
|
* will be empty. Secondly, free space at the end of an index LEB is not
|
|
* guaranteed to be empty because it may have been used by the in-the-gaps
|
|
* method prior to an unclean unmount.
|
|
*
|
|
* If no LEB is found %-ENOSPC is returned. For other failures another negative
|
|
* error code is returned.
|
|
*/
|
|
int ubifs_find_free_leb_for_idx(struct ubifs_info *c)
|
|
{
|
|
const struct ubifs_lprops *lprops;
|
|
int lnum = -1, err, flags;
|
|
|
|
ubifs_get_lprops(c);
|
|
|
|
lprops = ubifs_fast_find_empty(c);
|
|
if (!lprops) {
|
|
lprops = ubifs_fast_find_freeable(c);
|
|
if (!lprops) {
|
|
ubifs_assert(c->freeable_cnt == 0);
|
|
if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
|
|
lprops = scan_for_leb_for_idx(c);
|
|
if (IS_ERR(lprops)) {
|
|
err = PTR_ERR(lprops);
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!lprops) {
|
|
err = -ENOSPC;
|
|
goto out;
|
|
}
|
|
|
|
lnum = lprops->lnum;
|
|
|
|
dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
|
|
lnum, lprops->free, lprops->dirty, lprops->flags);
|
|
|
|
flags = lprops->flags | LPROPS_TAKEN | LPROPS_INDEX;
|
|
lprops = ubifs_change_lp(c, lprops, c->leb_size, 0, flags, 0);
|
|
if (IS_ERR(lprops)) {
|
|
err = PTR_ERR(lprops);
|
|
goto out;
|
|
}
|
|
|
|
ubifs_release_lprops(c);
|
|
|
|
/*
|
|
* Ensure that empty LEBs have been unmapped. They may not have been,
|
|
* for example, because of an unclean unmount. Also LEBs that were
|
|
* freeable LEBs (free + dirty == leb_size) will not have been unmapped.
|
|
*/
|
|
err = ubifs_leb_unmap(c, lnum);
|
|
if (err) {
|
|
ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
|
|
LPROPS_TAKEN | LPROPS_INDEX, 0);
|
|
return err;
|
|
}
|
|
|
|
return lnum;
|
|
|
|
out:
|
|
ubifs_release_lprops(c);
|
|
return err;
|
|
}
|
|
|
|
static int cmp_dirty_idx(const struct ubifs_lprops **a,
|
|
const struct ubifs_lprops **b)
|
|
{
|
|
const struct ubifs_lprops *lpa = *a;
|
|
const struct ubifs_lprops *lpb = *b;
|
|
|
|
return lpa->dirty + lpa->free - lpb->dirty - lpb->free;
|
|
}
|
|
|
|
static void swap_dirty_idx(struct ubifs_lprops **a, struct ubifs_lprops **b,
|
|
int size)
|
|
{
|
|
struct ubifs_lprops *t = *a;
|
|
|
|
*a = *b;
|
|
*b = t;
|
|
}
|
|
|
|
/**
|
|
* ubifs_save_dirty_idx_lnums - save an array of the most dirty index LEB nos.
|
|
* @c: the UBIFS file-system description object
|
|
*
|
|
* This function is called each commit to create an array of LEB numbers of
|
|
* dirty index LEBs sorted in order of dirty and free space. This is used by
|
|
* the in-the-gaps method of TNC commit.
|
|
*/
|
|
int ubifs_save_dirty_idx_lnums(struct ubifs_info *c)
|
|
{
|
|
int i;
|
|
|
|
ubifs_get_lprops(c);
|
|
/* Copy the LPROPS_DIRTY_IDX heap */
|
|
c->dirty_idx.cnt = c->lpt_heap[LPROPS_DIRTY_IDX - 1].cnt;
|
|
memcpy(c->dirty_idx.arr, c->lpt_heap[LPROPS_DIRTY_IDX - 1].arr,
|
|
sizeof(void *) * c->dirty_idx.cnt);
|
|
/* Sort it so that the dirtiest is now at the end */
|
|
sort(c->dirty_idx.arr, c->dirty_idx.cnt, sizeof(void *),
|
|
(int (*)(const void *, const void *))cmp_dirty_idx,
|
|
(void (*)(void *, void *, int))swap_dirty_idx);
|
|
dbg_find("found %d dirty index LEBs", c->dirty_idx.cnt);
|
|
if (c->dirty_idx.cnt)
|
|
dbg_find("dirtiest index LEB is %d with dirty %d and free %d",
|
|
c->dirty_idx.arr[c->dirty_idx.cnt - 1]->lnum,
|
|
c->dirty_idx.arr[c->dirty_idx.cnt - 1]->dirty,
|
|
c->dirty_idx.arr[c->dirty_idx.cnt - 1]->free);
|
|
/* Replace the lprops pointers with LEB numbers */
|
|
for (i = 0; i < c->dirty_idx.cnt; i++)
|
|
c->dirty_idx.arr[i] = (void *)(size_t)c->dirty_idx.arr[i]->lnum;
|
|
ubifs_release_lprops(c);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* scan_dirty_idx_cb - callback used by the scan for a dirty index LEB.
|
|
* @c: the UBIFS file-system description object
|
|
* @lprops: LEB properties to scan
|
|
* @in_tree: whether the LEB properties are in main memory
|
|
* @data: information passed to and from the caller of the scan
|
|
*
|
|
* 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_dirty_idx_cb(struct ubifs_info *c,
|
|
const struct ubifs_lprops *lprops, int in_tree,
|
|
struct scan_data *data)
|
|
{
|
|
int ret = LPT_SCAN_CONTINUE;
|
|
|
|
/* Exclude LEBs that are currently in use */
|
|
if (lprops->flags & LPROPS_TAKEN)
|
|
return LPT_SCAN_CONTINUE;
|
|
/* Determine whether to add these LEB properties to the tree */
|
|
if (!in_tree && valuable(c, lprops))
|
|
ret |= LPT_SCAN_ADD;
|
|
/* Exclude non-index LEBs */
|
|
if (!(lprops->flags & LPROPS_INDEX))
|
|
return ret;
|
|
/* Exclude LEBs with too little space */
|
|
if (lprops->free + lprops->dirty < c->min_idx_node_sz)
|
|
return ret;
|
|
/* Finally we found space */
|
|
data->lnum = lprops->lnum;
|
|
return LPT_SCAN_ADD | LPT_SCAN_STOP;
|
|
}
|
|
|
|
/**
|
|
* find_dirty_idx_leb - find a dirty index LEB.
|
|
* @c: the UBIFS file-system description object
|
|
*
|
|
* This function returns LEB number upon success and a negative error code upon
|
|
* failure. In particular, -ENOSPC is returned if a dirty index LEB is not
|
|
* found.
|
|
*
|
|
* Note that this function scans the entire LPT but it is called very rarely.
|
|
*/
|
|
static int find_dirty_idx_leb(struct ubifs_info *c)
|
|
{
|
|
const struct ubifs_lprops *lprops;
|
|
struct ubifs_lpt_heap *heap;
|
|
struct scan_data data;
|
|
int err, i, ret;
|
|
|
|
/* Check all structures in memory first */
|
|
data.lnum = -1;
|
|
heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
|
|
for (i = 0; i < heap->cnt; i++) {
|
|
lprops = heap->arr[i];
|
|
ret = scan_dirty_idx_cb(c, lprops, 1, &data);
|
|
if (ret & LPT_SCAN_STOP)
|
|
goto found;
|
|
}
|
|
list_for_each_entry(lprops, &c->frdi_idx_list, list) {
|
|
ret = scan_dirty_idx_cb(c, lprops, 1, &data);
|
|
if (ret & LPT_SCAN_STOP)
|
|
goto found;
|
|
}
|
|
list_for_each_entry(lprops, &c->uncat_list, list) {
|
|
ret = scan_dirty_idx_cb(c, lprops, 1, &data);
|
|
if (ret & LPT_SCAN_STOP)
|
|
goto found;
|
|
}
|
|
if (c->pnodes_have >= c->pnode_cnt)
|
|
/* All pnodes are in memory, so skip scan */
|
|
return -ENOSPC;
|
|
err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
|
|
(ubifs_lpt_scan_callback)scan_dirty_idx_cb,
|
|
&data);
|
|
if (err)
|
|
return err;
|
|
found:
|
|
ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
|
|
c->lscan_lnum = data.lnum;
|
|
lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
|
|
if (IS_ERR(lprops))
|
|
return PTR_ERR(lprops);
|
|
ubifs_assert(lprops->lnum == data.lnum);
|
|
ubifs_assert(lprops->free + lprops->dirty >= c->min_idx_node_sz);
|
|
ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
|
|
ubifs_assert((lprops->flags & LPROPS_INDEX));
|
|
|
|
dbg_find("found dirty LEB %d, free %d, dirty %d, flags %#x",
|
|
lprops->lnum, lprops->free, lprops->dirty, lprops->flags);
|
|
|
|
lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC,
|
|
lprops->flags | LPROPS_TAKEN, 0);
|
|
if (IS_ERR(lprops))
|
|
return PTR_ERR(lprops);
|
|
|
|
return lprops->lnum;
|
|
}
|
|
|
|
/**
|
|
* get_idx_gc_leb - try to get a LEB number from trivial GC.
|
|
* @c: the UBIFS file-system description object
|
|
*/
|
|
static int get_idx_gc_leb(struct ubifs_info *c)
|
|
{
|
|
const struct ubifs_lprops *lp;
|
|
int err, lnum;
|
|
|
|
err = ubifs_get_idx_gc_leb(c);
|
|
if (err < 0)
|
|
return err;
|
|
lnum = err;
|
|
/*
|
|
* The LEB was due to be unmapped after the commit but
|
|
* it is needed now for this commit.
|
|
*/
|
|
lp = ubifs_lpt_lookup_dirty(c, lnum);
|
|
if (IS_ERR(lp))
|
|
return PTR_ERR(lp);
|
|
lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
|
|
lp->flags | LPROPS_INDEX, -1);
|
|
if (IS_ERR(lp))
|
|
return PTR_ERR(lp);
|
|
dbg_find("LEB %d, dirty %d and free %d flags %#x",
|
|
lp->lnum, lp->dirty, lp->free, lp->flags);
|
|
return lnum;
|
|
}
|
|
|
|
/**
|
|
* find_dirtiest_idx_leb - find dirtiest index LEB from dirtiest array.
|
|
* @c: the UBIFS file-system description object
|
|
*/
|
|
static int find_dirtiest_idx_leb(struct ubifs_info *c)
|
|
{
|
|
const struct ubifs_lprops *lp;
|
|
int lnum;
|
|
|
|
while (1) {
|
|
if (!c->dirty_idx.cnt)
|
|
return -ENOSPC;
|
|
/* The lprops pointers were replaced by LEB numbers */
|
|
lnum = (size_t)c->dirty_idx.arr[--c->dirty_idx.cnt];
|
|
lp = ubifs_lpt_lookup(c, lnum);
|
|
if (IS_ERR(lp))
|
|
return PTR_ERR(lp);
|
|
if ((lp->flags & LPROPS_TAKEN) || !(lp->flags & LPROPS_INDEX))
|
|
continue;
|
|
lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
|
|
lp->flags | LPROPS_TAKEN, 0);
|
|
if (IS_ERR(lp))
|
|
return PTR_ERR(lp);
|
|
break;
|
|
}
|
|
dbg_find("LEB %d, dirty %d and free %d flags %#x", lp->lnum, lp->dirty,
|
|
lp->free, lp->flags);
|
|
ubifs_assert(lp->flags | LPROPS_TAKEN);
|
|
ubifs_assert(lp->flags | LPROPS_INDEX);
|
|
return lnum;
|
|
}
|
|
|
|
/**
|
|
* ubifs_find_dirty_idx_leb - try to find dirtiest index LEB as at last commit.
|
|
* @c: the UBIFS file-system description object
|
|
*
|
|
* This function attempts to find an untaken index LEB with the most free and
|
|
* dirty space that can be used without overwriting index nodes that were in the
|
|
* last index committed.
|
|
*/
|
|
int ubifs_find_dirty_idx_leb(struct ubifs_info *c)
|
|
{
|
|
int err;
|
|
|
|
ubifs_get_lprops(c);
|
|
|
|
/*
|
|
* We made an array of the dirtiest index LEB numbers as at the start of
|
|
* last commit. Try that array first.
|
|
*/
|
|
err = find_dirtiest_idx_leb(c);
|
|
|
|
/* Next try scanning the entire LPT */
|
|
if (err == -ENOSPC)
|
|
err = find_dirty_idx_leb(c);
|
|
|
|
/* Finally take any index LEBs awaiting trivial GC */
|
|
if (err == -ENOSPC)
|
|
err = get_idx_gc_leb(c);
|
|
|
|
ubifs_release_lprops(c);
|
|
return err;
|
|
}
|