+++ /dev/null
-/**
- * \file
- * <!--
- * This file is part of BeRTOS.
- *
- * Bertos is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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
- *
- * As a special exception, you may use this file as part of a free software
- * library without restriction. Specifically, if other files instantiate
- * templates or use macros or inline functions from this file, or you compile
- * this file and link it with other files to produce an executable, this
- * file does not by itself cause the resulting executable to be covered by
- * the GNU General Public License. This exception does not however
- * invalidate any other reasons why the executable file might be covered by
- * the GNU General Public License.
- *
- * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
- *
- * -->
- *
- * \version $Id:$
- *
- * \author Francesco Sacchi <batt@develer.com>
- *
- * \brief BattFS: a filesystem for embedded platforms (implementation).
- */
-
-#include "battfs.h"
-
-#include <cfg/debug.h>
-#include <cfg/macros.h> /* MIN, MAX */
-#include <mware/byteorder.h> /* cpu_to_xx */
-
-
-#include <string.h> /* memset, memmove */
-
-/**
- * Convert mark_t from cpu endianess to filesystem endianness.
- * \note filesystem is in little-endian format.
- */
-INLINE mark_t cpu_to_mark_t(mark_t mark)
-{
- STATIC_ASSERT(sizeof(mark_t) == 2);
- return cpu_to_le16(mark);
-}
-
-/**
- * Convert mark_t from filesystem endianness to cpu endianess.
- * \note filesystem is in little-endian format.
- */
-INLINE mark_t mark_t_to_cpu(mark_t mark)
-{
- STATIC_ASSERT(sizeof(mark_t) == 2);
- return le16_to_cpu(mark);
-}
-
-/**
- * Convert from cpu endianess to filesystem endianness.
- * \note filesystem is in little-endian format.
- */
-INLINE void cpu_to_battfs(struct BattFsPageHeader *hdr)
-{
- STATIC_ASSERT(sizeof(hdr->inode) == 1);
- STATIC_ASSERT(sizeof(hdr->seq) == 1);
-
- hdr->mark = cpu_to_mark_t(hdr->mark);
-
- STATIC_ASSERT(sizeof(hdr->fill) == 2);
- hdr->fill = cpu_to_le16(hdr->fill);
-
- STATIC_ASSERT(sizeof(hdr->pgoff) == 2);
- hdr->pgoff = cpu_to_le16(hdr->pgoff);
-
- STATIC_ASSERT(sizeof(hdr->fcs) == 2);
- hdr->fcs = cpu_to_le16(hdr->fcs);
-
- STATIC_ASSERT(sizeof(hdr->rfu) == 2);
- hdr->rfu = cpu_to_le16(hdr->rfu);
-}
-
-
-/**
- * Convert from filesystem endianness to cpu endianess.
- * \note filesystem is in little-endian format.
- */
-INLINE void battfs_to_cpu(struct BattFsPageHeader *hdr)
-{
- STATIC_ASSERT(sizeof(hdr->inode) == 1);
- STATIC_ASSERT(sizeof(hdr->seq) == 1);
-
- hdr->mark = mark_t_to_cpu(hdr->mark);
-
- STATIC_ASSERT(sizeof(hdr->fill) == 2);
- hdr->fill = le16_to_cpu(hdr->fill);
-
- STATIC_ASSERT(sizeof(hdr->pgoff) == 2);
- hdr->pgoff = le16_to_cpu(hdr->pgoff);
-
- STATIC_ASSERT(sizeof(hdr->fcs) == 2);
- hdr->fcs = le16_to_cpu(hdr->fcs);
-
- STATIC_ASSERT(sizeof(hdr->rfu) == 2);
- hdr->rfu = le16_to_cpu(hdr->rfu);
-}
-
-
-/**
- * Read header of page \a page.
- * \return true on success, false otherwise.
- * \note \a hdr is dirtyed even on errors.
- */
-static bool battfs_readHeader(struct BattFsSuper *disk, pgcnt_t page, struct BattFsPageHeader *hdr)
-{
- /*
- * Read header from disk.
- * header is actually a footer, and so
- * resides at page end.
- */
- if (disk->read(disk, page, disk->page_size - sizeof(BattFsPageHeader), hdr, sizeof(BattFsPageHeader))
- != sizeof(BattFsPageHeader))
- {
- TRACEMSG("Error: page[%d]\n", page);
- return false;
- }
-
- /* Fix endianess */
- battfs_to_cpu(hdr);
-
- return true;
-}
-
-/**
- * Count the number of pages from
- * inode 0 to \a inode in \a filelen_table.
- */
-static pgcnt_t countPages(pgoff_t *filelen_table, inode_t inode)
-{
- pgcnt_t cnt = 0;
-
- for (inode_t i = 0; i < inode; i++)
- cnt += filelen_table[i];
-
- return cnt;
-}
-
-/**
- * Move all pages in page allocation array from \a src to \a src + \a offset.
- * The number of pages moved is page_count - MAX(dst, src).
- */
-static void movePages(struct BattFsSuper *disk, pgcnt_t src, int offset)
-{
- pgcnt_t dst = src + offset;
- memmove(&disk->page_array[dst], &disk->page_array[src], disk->page_count - MAX(dst, src) * sizeof(pgcnt_t));
-
- if (offset < 0)
- {
- /* Fill empty space in array with sentinel */
- for (pgcnt_t page = disk->page_count + offset; page < disk->page_count; page++)
- disk->page_array[page] = PAGE_UNSET_SENTINEL;
- }
-}
-
-/**
- * Insert \a page into page allocation array of \a disk, using \a filelen_table and
- * \a free_number to compure position.
- */
-static void insertFreePage(struct BattFsSuper *disk, pgoff_t *filelen_table, mark_t free_number, pgcnt_t page)
-{
- ASSERT(mark >= disk->min_free);
- ASSERT(mark <= disk->max_free);
-
- pgcnt_t free_pos = countPages(filelen_table, BATTFS_MAX_FILES - 1);
- free_pos += free_number - disk->min_free;
- ASSERT(disk->page_array[free_pos] == PAGE_UNSET_SENTINEL);
- disk->page_array[free_pos] = page;
-}
-
-/**
- * Mark \a page of \a disk as free.
- * \note max_free of \a disk is increased by 1 and is used as
- * \a page free marker.
- */
-static bool battfs_markFree(struct BattFsSuper *disk, pgcnt_t page)
-{
- pgaddr_t addr = disk->page_size - sizeof(BattFsPageHeader) + offsetof(BattFsPageHeader, mark);
- mark_t mark = cpu_to_mark_t(++disk->max_free);
- if (!disk->write(disk, page, addr, &mark, sizeof(mark)))
- {
- TRACEMSG("error marking page [%d]\n", page);
- return false;
- }
- else
- return true;
-}
-
-
-/**
- * Initialize and mount disk described by
- * \a d.
- * \return false on errors, true otherwise.
- */
-bool battfs_init(struct BattFsSuper *disk)
-{
- BattFsPageHeader hdr;
- rotating_t cks;
- pgoff_t filelen_table[BATTFS_MAX_FILES];
-
- /* Sanity checks */
- ASSERT(disk->open);
- ASSERT(disk->read);
- ASSERT(disk->write);
- ASSERT(disk->erase);
- ASSERT(disk->close);
- ASSERT(disk->page_size);
- ASSERT(disk->page_count);
- ASSERT(disk->page_count < PAGE_UNSET_SENTINEL - 1);
- ASSERT(disk->page_array);
-
- /* Init disk device */
- if (!disk->open(disk))
- {
- TRACEMSG("open error\n");
- return false;
- }
-
- memset(filelen_table, 0, BATTFS_MAX_FILES * sizeof(pgoff_t));
-
- /* Initialize min free sequence number to max value */
- disk->min_free = MARK_PAGE_VALID;
- /* Initialize max free sequence number to min value */
- disk->max_free = 0;
-
- disk->free_bytes = 0;
- disk->disk_size = (disk_size_t)(disk->page_size - sizeof(BattFsPageHeader)) * disk->page_count;
-
- /* Count the number of disk page per files */
- for (pgcnt_t page = 0; page < disk->page_count; page++)
- {
- if (!battfs_readHeader(disk, page, &hdr))
- return false;
-
- /* Check header FCS */
- rotating_init(&cks);
- rotating_update(&hdr, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks);
- if (cks == hdr.fcs)
- {
- /* Page is valid and is owned by a file */
- filelen_table[hdr.inode]++;
-
- ASSERT(hdr.mark == MARK_PAGE_VALID);
- ASSERT(hdr.fill <= disk->page_size - sizeof(BattFsPageHeader));
- /* Keep trace of free space */
- disk->free_bytes += disk->page_size - sizeof(BattFsPageHeader) - hdr.fill;
- }
- else
- {
- /* Increase free space */
- disk->free_bytes += disk->page_size - sizeof(BattFsPageHeader);
-
- /* Check if putting mark to MARK_PAGE_VALID makes fcs correct */
- mark_t old_mark = hdr.mark;
- hdr.mark = MARK_PAGE_VALID;
- rotating_init(&cks);
- rotating_update(&hdr, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks);
- if (cks == hdr.fcs)
- {
- /*
- * This page is a valid and marked free page.
- * Update min and max free page sequence numbers.
- */
- disk->min_free = MIN(disk->min_free, old_mark);
- disk->max_free = MAX(disk->max_free, old_mark);
- }
- else
- TRACEMSG("page [%d] invalid, keeping as free\n", page);
- }
- }
-
- /* Once here, we have filelen_table filled with file lengths */
-
- /* Fill page array with sentinel */
- for (pgcnt_t page = 0; page < disk->page_count; page++)
- disk->page_array[page] = PAGE_UNSET_SENTINEL;
-
- /* Fill page allocation array */
- for (pgcnt_t page = 0; page < disk->page_count; page++)
- {
- if (!battfs_readHeader(disk, page, &hdr))
- return false;
-
- /* Check header FCS */
- rotating_init(&cks);
- rotating_update(&hdr, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks);
- if (cks == hdr.fcs)
- {
- /* Page is valid and is owned by a file */
- ASSERT(hdr.mark == MARK_PAGE_VALID);
-
- /* Compute array position */
- pgcnt_t array_pos = countPages(filelen_table, hdr.inode);
- array_pos += hdr.pgoff;
-
- /* Check if position is already used by another page of the same file */
- if (disk->page_array[array_pos] == PAGE_UNSET_SENTINEL)
- disk->page_array[array_pos] = page;
- else
- {
- BattFsPageHeader hdr_old;
-
- if (!battfs_readHeader(disk, disk->page_array[array_pos], &hdr_old))
- return false;
-
- #ifdef _DEBUG
- /* Check header FCS */
- rotating_t cks_old;
- rotating_init(&cks_old);
- rotating_update(&hdr_old, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks_old);
- ASSERT(cks_old == hdr_old.fcs);
- #endif
-
- /* Only the very same page with a different seq number can be here */
- ASSERT(hdr.inode == hdr_old.inode);
- ASSERT(hdr.pgoff == hdr_old.pgoff);
- ASSERT(hdr.mark == hdr_old.mark);
- ASSERT(hdr.seq != hdr_old.seq);
-
- pgcnt_t new_page, old_page;
- fill_t old_fill;
-
- /* Fancy check to handle seq wraparound */
- #define HALF_SEQ ((1 << (sizeof(seq_t) * CPU_BITS_PER_CHAR)) / 2)
- if ((hdr.seq - hdr_old.seq) < HALF_SEQ)
- {
- /* Actual header is newer than the previuos one */
- old_page = disk->page_array[array_pos];
- new_page = page;
- old_fill = hdr_old.fill;
- }
- else
- {
- /* Previous header is newer than the current one */
- old_page = page;
- new_page = disk->page_array[array_pos];
- old_fill = hdr.fill;
- }
-
- /* Set new page */
- disk->page_array[array_pos] = new_page;
-
- /* Add free space */
- disk->free_bytes += old_fill;
-
- /* Shift all array one position to the left, overwriting duplicate page */
- array_pos -= hdr.pgoff;
- array_pos += filelen_table[hdr.inode];
- movePages(disk, array_pos, -1);
-
- /* Decrease file page count */
- filelen_table[hdr.inode]--;
-
- /* Add old page to free pages pool */
- if (!battfs_markFree(disk, old_page))
- return false;
-
- insertFreePage(disk, filelen_table, disk->max_free, old_page);
- }
- }
- else
- {
- /* Check if putting mark to MARK_PAGE_VALID makes fcs correct */
- mark_t mark = hdr.mark;
- hdr.mark = MARK_PAGE_VALID;
- rotating_init(&cks);
- rotating_update(&hdr, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks);
- if (cks != hdr.fcs)
- /* Page is not a valid marked page, insert at the end of list */
- mark = ++disk->max_free;
-
- insertFreePage(disk, filelen_table, mark, page);
- }
- }
-
- #warning Test me!
- return true;
-}
-
-
projects / bertos.git / blobdiff