X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=fs%2Fbattfs.c;h=93a8868e868b66e5b3950dddaf78f5382b996436;hb=HEAD;hp=9923cc273cdd2d559d00c1bfc0ff9675598b7f48;hpb=61dc36aa9fe6086e7ed3f37e8e4953a1ed5cf1a5;p=bertos.git diff --git a/fs/battfs.c b/fs/battfs.c deleted file mode 100644 index 9923cc27..00000000 --- a/fs/battfs.c +++ /dev/null @@ -1,473 +0,0 @@ -/** - * \file - * - * - * \version $Id:$ - * - * \author Francesco Sacchi - * - * \brief BattFS: a filesystem for embedded platforms (implementation). - */ - -#include "battfs.h" - -#include -#include /* MIN, MAX */ -#include /* cpu_to_xx */ - - -#include /* memset, memmove */ - - -/** - * Convert from memory representation to disk structure. - * \note filesystem is in little-endian format. - */ -INLINE void battfs_to_disk(struct BattFsPageHeader *hdr, uint8_t *buf) -{ - STATIC_ASSERT(BATTFS_HEADER_LEN == 12); - buf[0] = hdr->inode; - - buf[1] = hdr->fill; - buf[2] = hdr->fill >> 8; - - buf[3] = hdr->pgoff; - buf[4] = hdr->pgoff >> 8; - - /* - * Mark is at least 1 bit longer than page address. - * Needed to take care of wraparonds. - */ - buf[5] = hdr->mark; - buf[6] = hdr->mark >> 8; - - /* - * First bit used by mark, last 2 bits used by seq. - * Since only 2 pages with the same inode and pgoff - * can exist at the same time, 2 bit for seq are enough. - */ - buf[7] = ((hdr->mark >> 16) & 0x01) | (hdr->seq << 6); - - /* - * This field must be the before the last one! - */ - buf[8] = hdr->fcs_free; - buf[9] = hdr->fcs_free >> 8; - - /* - * This field must be the last one! - * This is needed because if the page is only partially - * written, we can use this to detect it. - */ - buf[10] = hdr->fcs; - buf[11] = hdr->fcs >> 8; -} - -/** - * Convert from disk structure to memory representation. - * \note filesystem is in little-endian format. - */ -INLINE void disk_to_battfs(uint8_t *buf, struct BattFsPageHeader *hdr) -{ - STATIC_ASSERT(BATTFS_HEADER_LEN == 12); - hdr->inode = buf[0]; - hdr->fill = buf[2] << 8 | buf[1]; - hdr->pgoff = buf[4] << 8 | buf[3]; - hdr->mark = (mark_t)(buf[7] & 0x01) << 16 | buf[6] << 8 | buf[5]; - hdr->seq = buf[7] >> 6; - hdr->fcs_free = buf[9] << 8 | buf[8]; - hdr->fcs = buf[11] << 8 | buf[10]; -} - -/** - * Compute the fcs of the header. - */ -static fcs_t computeFcs(struct BattFsPageHeader *hdr) -{ - uint8_t buf[BATTFS_HEADER_LEN]; - fcs_t cks; - - battfs_to_disk(hdr, buf); - rotating_init(&cks); - /* fcs is at the end of whole header */ - rotating_update(buf,BATTFS_HEADER_LEN - sizeof(fcs_t), &cks); - return cks; -} - -/** - * Compute the fcs of the header marked as free. - */ -static fcs_t computeFcsFree(struct BattFsPageHeader *hdr) -{ - uint8_t buf[BATTFS_HEADER_LEN]; - fcs_t cks; - - battfs_to_disk(hdr, buf); - rotating_init(&cks); - /* fcs_free is just before fcs of whole header */ - rotating_update(buf,BATTFS_HEADER_LEN - 2 * sizeof(fcs_t), &cks); - return cks; -} - - -/** - * 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) -{ - uint8_t buf[BATTFS_HEADER_LEN]; - /* - * Read header from disk. - * Header is actually a footer, and so - * resides at page end. - */ - if (disk->read(disk, page, disk->page_size - BATTFS_HEADER_LEN - 1, buf, BATTFS_HEADER_LEN) - != BATTFS_HEADER_LEN) - { - TRACEMSG("Error: page[%d]\n", page); - return false; - } - - /* Fill header */ - disk_to_battfs(buf, 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 compute position. - */ -static void insertFreePage(struct BattFsSuper *disk, mark_t mark, pgcnt_t page) -{ - ASSERT(mark - disk->free_start < disk->free_next - disk->free_start); - - pgcnt_t free_pos = disk->page_count - disk->free_next + mark; - ASSERT(free_pos < disk->page_count); - - TRACEMSG("mark:%u, page:%u, free_start:%u, free_next:%u, free_pos:%u\n", - mark, page, disk->free_start, disk->free_next, free_pos); - - ASSERT(disk->page_array[free_pos] == PAGE_UNSET_SENTINEL); - disk->page_array[free_pos] = page; -} - -/** - * Mark \a page of \a disk as free. - * \note free_next of \a disk is used as \a page free marker - * and is increased by 1. - */ -static bool battfs_markFree(struct BattFsSuper *disk, struct BattFsPageHeader *hdr, pgcnt_t page) -{ - uint8_t buf[BATTFS_HEADER_LEN]; - - hdr->mark = disk->free_next; - hdr->fcs_free = computeFcsFree(hdr); - battfs_to_disk(hdr, buf); - - if (!disk->write(disk, page, disk->page_size - BATTFS_HEADER_LEN - 1, buf, BATTFS_HEADER_LEN)) - { - TRACEMSG("error marking page [%d]\n", page); - return false; - } - else - { - disk->free_next++; - return true; - } -} - - -/** - * Initialize and mount disk described by - * \a d. - * \return false on errors, true otherwise. - */ -bool battfs_init(struct BattFsSuper *disk) -{ - BattFsPageHeader hdr; - pgoff_t filelen_table[BATTFS_MAX_FILES]; - mark_t minl, maxl, minh, maxh; - - /* Sanity check */ - ASSERT(disk->open); - - /* Init disk device */ - if (!disk->open(disk)) - { - TRACEMSG("open error\n"); - return false; - } - - /* Disk open must set all of these */ - 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); - - memset(filelen_table, 0, BATTFS_MAX_FILES * sizeof(pgoff_t)); - - /* Initialize min and max counters to keep trace od free blocks */ - minl = MAX_PAGE_ADDR; - maxl = 0; - minh = MAX_PAGE_ADDR | MARK_HALF_SIZE; - maxh = 0 | MARK_HALF_SIZE; - - disk->free_bytes = 0; - disk->disk_size = (disk_size_t)(disk->page_size - BATTFS_HEADER_LEN) * disk->page_count; - - /* Count the number of disk page per file */ - for (pgcnt_t page = 0; page < disk->page_count; page++) - { - if (!battfs_readHeader(disk, page, &hdr)) - return false; - - /* Check header FCS */ - if (hdr.fcs == computeFcs(&hdr)) - { - ASSERT(hdr.mark == MARK_PAGE_VALID); - ASSERT(hdr.fcs_free == FCS_FREE_VALID); - ASSERT(hdr.fill <= disk->page_size - BATTFS_HEADER_LEN); - - /* Page is valid and is owned by a file */ - filelen_table[hdr.inode]++; - - /* Keep trace of free space */ - disk->free_bytes += disk->page_size - BATTFS_HEADER_LEN - hdr.fill; - } - else - { - /* Increase free space */ - disk->free_bytes += disk->page_size - BATTFS_HEADER_LEN; - - /* Check if page is marked free */ - if (hdr.fcs_free == computeFcsFree(&hdr)) - { - /* - * This page is a valid and marked free page. - * Update min and max free page markers. - */ - if (hdr.mark < MARK_HALF_SIZE) - { - minl = MIN(minl, hdr.mark); - maxl = MAX(maxl, hdr.mark); - } - else - { - minh = MIN(minh, hdr.mark); - maxh = MAX(maxh, hdr.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; - - /* Determine free_start & free_next */ - if (maxl >= minl) - { - if (maxh >= minh) - { - if (maxl == minh - 1) - { - disk->free_start = minl; - disk->free_next = maxh; - } - else - { - ASSERT(minl == 0); - ASSERT(maxh == (MAX_PAGE_ADDR | MARK_HALF_SIZE)); - - disk->free_start = minh; - disk->free_next = maxl; - } - } - else - { - disk->free_start = minl; - disk->free_next = maxl; - } - } - else if (maxh >= minh) - { - disk->free_start = minh; - disk->free_next = maxh; - } - else - { - TRACEMSG("No valid marked free block found\n"); - disk->free_start = 0; - disk->free_next = -1; //to be incremented ahead - } - - /* free_next should contain the first usable address */ - disk->free_next++; - - TRACEMSG("Free markers:\n minl %u\n maxl %u\n minh %u\n maxh %u\n free_start %u\n free_next %u\n", - minl, maxl, minh, maxh, disk->free_start, disk->free_next); - - - /* 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 */ - if (hdr.fcs == computeFcs(&hdr)) - { - /* Page is valid and is owned by a file */ - ASSERT(hdr.mark == MARK_PAGE_VALID); - ASSERT(hdr.fcs_free == FCS_FREE_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 (LIKELY(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; - - /* Check header FCS */ - ASSERT(hdr_old.fcs == computeFcs(&hdr_old)); - - /* 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.fcs_free == hdr_old.fcs_free); - ASSERT(hdr.seq != hdr_old.seq); - - pgcnt_t new_page, old_page; - fill_t old_fill; - - /* Fancy check to handle seq wraparound (2 bits only) */ - if (((hdr.seq - hdr_old.seq) & 0x03) < 2) - { - /* Current 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, &hdr, old_page)) - return false; - - insertFreePage(disk, hdr.mark, old_page); - } - } - else - { - /* Check if page is free */ - if (hdr.fcs_free != computeFcsFree(&hdr)) - /* Page is not a valid marked page, insert at list beginning */ - hdr.mark = --disk->free_start; - - insertFreePage(disk, hdr.mark, page); - } - } - - #warning Test me! - return true; -} - -