X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=fs%2Fbattfs.c;h=93a8868e868b66e5b3950dddaf78f5382b996436;hb=HEAD;hp=6cece9f351913019c03a1849bff6b807216f5231;hpb=10b8ef799ea20d9111f8800e387a79713b8a174b;p=bertos.git diff --git a/fs/battfs.c b/fs/battfs.c deleted file mode 100644 index 6cece9f3..00000000 --- a/fs/battfs.c +++ /dev/null @@ -1,818 +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. - * Unused bits are set to 1. - */ - buf[7] = ((hdr->mark >> 16) & 0x01) | (hdr->seq << 6) | ~(BV(7) | BV(6) | BV(0)); - - /* - * 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, buf, BATTFS_HEADER_LEN) - != BATTFS_HEADER_LEN) - { - TRACEMSG("Error: page[%d]\n", page); - return false; - } - - /* Fill header */ - disk_to_battfs(buf, hdr); - - return true; -} - -/** - * Write header of page \a page. - * \return true on success, false otherwise. - * \note \a hdr is dirtyed even on errors. - */ -static bool battfs_writeHeader(struct BattFsSuper *disk, pgcnt_t page, struct BattFsPageHeader *hdr) -{ - uint8_t buf[BATTFS_HEADER_LEN]; - - /* Fill buffer */ - battfs_to_disk(hdr, buf); - - /* - * write header to disk. - * Header is actually a footer, and so - * resides at page end. - */ - if (disk->write(disk, page, disk->page_size - BATTFS_HEADER_LEN, buf, BATTFS_HEADER_LEN) - != BATTFS_HEADER_LEN) - { - TRACEMSG("Error: page[%d]\n", page); - return false; - } - 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 mark 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, buf, BATTFS_HEADER_LEN)) - { - TRACEMSG("error marking page [%d]\n", page); - return false; - } - else - { - disk->free_next++; - return true; - } -} - -/** - * Determine free_start and free_next blocks for \a disk - * using \a minl, \a maxl, \a minh, \a maxh. - * - * Mark_t is a type that has at least 1 bit more than - * pgaddr_t. So all free blocks can be numbered using - * at most half numbers of a mark_t type. - * The free blocks algorithm increments by 1 the disk->free_next - * every time a page becomes free. So the free block sequence is - * guaranteed to be countiguous. - * Only wrap arounds may happen, but due to half size sequence limitation, - * there are only 4 possible situations: - * - * \verbatim - * |------lower half------|-------upper half-------| - * - * 1) |------minl*****maxl---|------------------------| - * 2) |------minl********maxl|minh******maxh----------| - * 3) |----------------------|----minh*******maxh-----| - * 4) |minl******maxl--------|------------minh****maxh| - * \endverbatim - * - * Situations 1 and 3 are easy to detect, while 2 and 4 require more care. - */ -static void findFreeStartNext(struct BattFsSuper *disk, mark_t minl, mark_t maxl, mark_t minh, mark_t maxh) -{ - /* Determine free_start & free_next */ - if (maxl >= minl) - { - /* Valid interval found in lower half */ - if (maxh >= minh) - { - /* Valid interval also found in upper half */ - if (maxl == minh - 1) - { - /* Interval starts in lower half and ends in upper */ - disk->free_start = minl; - disk->free_next = maxh; - } - else - { - /* Interval starts in upper half and ends in lower */ - ASSERT(minl == 0); - ASSERT(maxh == (MAX_PAGE_ADDR | MARK_HALF_SIZE)); - - disk->free_start = minh; - disk->free_next = maxl; - } - } - else - { - /* - * Upper interval is invalid. - * Use lower values. - */ - - disk->free_start = minl; - disk->free_next = maxl; - } - } - else if (maxh >= minh) - { - /* - * Lower interval is invalid. - * Use upper values. - */ - disk->free_start = minh; - disk->free_next = maxh; - } - else - { - /* - * No valid interval found. - * Hopefully the disk is brand new (or full). - */ - TRACEMSG("No valid marked free block found, new disk or disk full\n"); - disk->free_start = 0; - disk->free_next = -1; //to be increased later - } - - /* 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); -} - -/** - * Count number of pages per file on \a disk. - * This information is registered in \a filelen_table. - * Array index represent file inode, while value contained - * is the number of pages used by that file. - * - * \return true if ok, false on disk read errors. - * \note The whole disk is scanned once. - */ -static bool countDiskFilePages(struct BattFsSuper *disk, pgoff_t *filelen_table) -{ - BattFsPageHeader hdr; - mark_t minl, maxl, minh, maxh; - - /* 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; - - - /* 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); - } - } - findFreeStartNext(disk, minl, maxl, minh, maxh); - return true; -} - -/** - * Fill page allocation array of \a disk - * using file lenghts in \a filelen_table. - * - * The page allocation array is an array containings all file infos. - * Is ordered by file, and within each file is ordered by page offset - * inside file. - * e.g. : at page array[0] you will find page address of the first page - * of the first file (if present). - * Free blocks are allocated after the last file, starting from invalid ones - * and continuing with the marked free ones. - * - * \return true if ok, false on disk read errors. - * \note The whole disk is scanned once. - */ -static bool fillPageArray(struct BattFsSuper *disk, pgoff_t *filelen_table) -{ - BattFsPageHeader hdr; - /* 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); - } - } - return true; -} - -/** - * Initialize and mount disk described by - * \a disk. - * \return false on errors, true otherwise. - */ -bool battfs_init(struct BattFsSuper *disk) -{ - pgoff_t filelen_table[BATTFS_MAX_FILES]; - - /* 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)); - - disk->free_bytes = 0; - disk->disk_size = (disk_size_t)(disk->page_size - BATTFS_HEADER_LEN) * disk->page_count; - - /* Count pages per file */ - if (!countDiskFilePages(disk, filelen_table)) - { - TRACEMSG("error counting file pages\n"); - return false; - } - - /* 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 using filelen_table */ - if (!fillPageArray(disk, filelen_table)) - { - TRACEMSG("error filling page array\n"); - return false; - } - - /* Init list for opened files. */ - LIST_INIT(&disk->file_opened_list); - return true; -} - -/** - * Flush file \a fd. - * \return 0 if ok, EOF on errors. - */ -static int battfs_flush(struct KFile *fd) -{ - (void)fd; - #warning TODO - return 0; -} - -/** - * Close file \a fd. - * \return 0 if ok, EOF on errors. - */ -static int battfs_fileclose(struct KFile *fd) -{ - KFileBattFs *fdb = KFILEBATTFS(fd); - - battfs_flush(fd); - REMOVE(&fdb->link); - return 0; -} - -/** - * Read from file \a fd \a size bytes in \a buf. - * \return The number of bytes read. - */ -static size_t battfs_read(struct KFile *fd, void *_buf, size_t size) -{ - KFileBattFs *fdb = KFILEBATTFS(fd); - uint8_t *buf = (uint8_t *)_buf; - - size_t total_read = 0; - pgoff_t pg_offset; - pgaddr_t addr_offset; - pgaddr_t read_len; - - size = MIN(size, fd->size - fd->seek_pos); - - while (size) - { - pg_offset = fd->seek_pos / (fdb->disk->page_size - BATTFS_HEADER_LEN); - addr_offset = fd->seek_pos % (fdb->disk->page_size - BATTFS_HEADER_LEN); - read_len = MIN(size, (size_t)(fdb->disk->page_size - BATTFS_HEADER_LEN - addr_offset)); - - /* Read from disk */ - if (fdb->disk->read(fdb->disk, fdb->start[pg_offset], addr_offset, buf, read_len) != read_len) - { - #warning TODO set error? - } - - size -= read_len; - fd->seek_pos += read_len; - total_read += read_len; - buf += read_len; - } - return total_read; -} - - -/** - * Search file \a inode in \a disk using a binary search. - * \return pointer to file start in disk->page_array - * if file exists, NULL otherwise. - */ -static pgcnt_t *findFile(BattFsSuper *disk, inode_t inode) -{ - BattFsPageHeader hdr; - pgcnt_t first = 0, page, last = disk->page_count -1; - fcs_t fcs; - - while (first <= last) - { - page = (first + last) / 2; - - if (!battfs_readHeader(disk, disk->page_array[page], &hdr)) - return NULL; - - fcs = computeFcs(&hdr); - if (hdr.fcs == fcs && hdr.inode == inode) - return (&disk->page_array[page]) - hdr.pgoff; - else if (hdr.fcs == fcs && hdr.inode < inode) - first = page + 1; - else - last = page - 1; - } - - return NULL; -} - -/** - * Count size of file \a inode on \a disk, starting at pointer \a start - * in disk->page_array. Size is written in \a size. - * \return true if all s ok, false on disk read errors. - */ -static bool countFileSize(BattFsSuper *disk, pgcnt_t *start, inode_t inode, file_size_t *size) -{ - *size = 0; - BattFsPageHeader hdr; - - for (;;) - { - if (!battfs_readHeader(disk, *start++, &hdr)) - return false; - if (hdr.fcs == computeFcs(&hdr) && hdr.inode == inode) - *size += hdr.fill; - else - return true; - } -} - -/** - * Open file \a inode from \a disk in \a mode. - * File context is stored in \a fd. - * \return true if ok, false otherwise. - */ -bool battfs_fileopen(BattFsSuper *disk, KFileBattFs *fd, inode_t inode, filemode_t mode) -{ - Node *n; - - memset(fd, 0, sizeof(*fd)); - - /* Search file start point in disk page array */ - fd->start = findFile(disk, inode); - if (fd->start == NULL) - { - if (!(mode & BATTFS_CREATE)) - return false; - - /* File does not exist, create it */ - BattFsPageHeader hdr; - hdr.inode = inode; - hdr.seq = 0; - hdr.fill = 0; - hdr.pgoff = 0; - hdr.mark = MARK_PAGE_VALID; - hdr.fcs_free = FCS_FREE_VALID; - hdr.fcs = computeFcs(&hdr); - #warning TODO: get a free block and write on disk! - } - - /* Fill file size */ - if (!countFileSize(disk, fd->start, inode, &fd->fd.size)) - return false; - - /* Reset seek position */ - fd->fd.seek_pos = 0; - - /* Insert file handle in list, ordered by inode, ascending. */ - FOREACH_NODE(n, &disk->file_opened_list) - { - KFileBattFs *file = containerof(n, KFileBattFs, link); - if (file->inode >= inode) - break; - } - INSERT_BEFORE(n, &fd->link); - - /* Fill in data */ - fd->inode = inode; - fd->mode = mode; - fd->disk = disk; - - fd->fd.close = battfs_fileclose; - fd->fd.flush = battfs_flush; - fd->fd.read = battfs_read; - fd->fd.reopen = kfile_genericReopen; - fd->fd.seek = kfile_genericSeek; - -#warning TODO battfs_write, battfs_error, battfs_clearerr -#if 0 - fd->fd.write = battfs_write; - fd->fd.error = battfs_error; - fd->fd.clearerr = battfs_clearerr; -#endif - - DB(fd->fd._type = KFT_BATTFS); - - return true; -} - -/** - * Close \a disk. - */ -bool battfs_close(struct BattFsSuper *disk) -{ - Node *n; - int res = 0; - - /* Close all open files */ - FOREACH_NODE(n, &disk->file_opened_list) - { - KFileBattFs *file = containerof(n, KFileBattFs, link); - res += battfs_fileclose(&file->fd); - } - - /* Close disk */ - return disk->close(disk) && (res == 0); -} - - -bool battfs_writeTestBlock(struct BattFsSuper *disk, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff, mark_t mark) -{ - BattFsPageHeader hdr; - - hdr.inode = inode; - hdr.seq = seq; - hdr.fill = fill; - hdr.pgoff = pgoff; - hdr.mark = MARK_PAGE_VALID; - hdr.fcs_free = FCS_FREE_VALID; - hdr.fcs = computeFcs(&hdr); - if (mark != MARK_PAGE_VALID) - { - hdr.mark = mark; - hdr.fcs_free = computeFcsFree(&hdr); - } - - if (!battfs_writeHeader(disk, page, &hdr)) - { - TRACEMSG("error writing hdr\n"); - return false; - } - - return true; -}