4 * This file is part of BeRTOS.
6 * Bertos is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * As a special exception, you may use this file as part of a free software
21 * library without restriction. Specifically, if other files instantiate
22 * templates or use macros or inline functions from this file, or you compile
23 * this file and link it with other files to produce an executable, this
24 * file does not by itself cause the resulting executable to be covered by
25 * the GNU General Public License. This exception does not however
26 * invalidate any other reasons why the executable file might be covered by
27 * the GNU General Public License.
29 * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
33 * \brief BattFS: a filesystem for embedded platforms (implementation).
37 * \author Francesco Sacchi <batt@develer.com>
43 #include <cfg/debug.h>
44 #include <cfg/macros.h> /* MIN, MAX */
45 #include <cpu/byteorder.h> /* cpu_to_xx */
47 #define LOG_LEVEL LOG_LVL_INFO
48 #define LOG_FORMAT LOG_FMT_VERBOSE
51 #include <string.h> /* memset, memmove */
53 #if LOG_LEVEL >= LOG_LVL_INFO
54 static void dumpPageArray(struct BattFsSuper *disk)
56 kprintf("Page array dump, free_page_start %d:", disk->free_page_start);
57 for (pgcnt_t i = 0; i < disk->page_count; i++)
61 kprintf("%04d ", disk->page_array[i]);
68 * Convert from memory representation to disk structure.
69 * \note filesystem is in little-endian format.
71 INLINE void battfs_to_disk(struct BattFsPageHeader *hdr, uint8_t *buf)
73 STATIC_ASSERT(BATTFS_HEADER_LEN == 12);
77 buf[2] = hdr->fill >> 8;
80 buf[4] = hdr->pgoff >> 8;
83 * Sequence number is 40 bits long.
84 * No need to take care of wraparonds: the memory will die first!
87 buf[6] = hdr->seq >> 8;
88 buf[7] = hdr->seq >> 16;
89 buf[8] = hdr->seq >> 24;
90 buf[9] = hdr->seq >> 32;
93 * This field must be the last one!
94 * This is needed because if the page is only partially
95 * written, we can use this to detect it.
98 buf[11] = hdr->fcs >> 8;
102 * Convert from disk structure to memory representation.
103 * \note filesystem is in little-endian format.
105 INLINE void disk_to_battfs(uint8_t *buf, struct BattFsPageHeader *hdr)
107 STATIC_ASSERT(BATTFS_HEADER_LEN == 12);
109 hdr->fill = buf[2] << 8 | buf[1];
110 hdr->pgoff = buf[4] << 8 | buf[3];
111 hdr->seq = (seq_t)buf[9] << 32 | (seq_t)buf[8] << 24 | (seq_t)buf[7] << 16 | buf[6] << 8 | buf[5];
112 hdr->fcs = buf[11] << 8 | buf[10];
116 * Compute the fcs of the header.
118 static fcs_t computeFcs(struct BattFsPageHeader *hdr)
120 uint8_t buf[BATTFS_HEADER_LEN];
123 battfs_to_disk(hdr, buf);
125 /* fcs is at the end of whole header */
126 rotating_update(buf, BATTFS_HEADER_LEN - sizeof(fcs_t), &cks);
132 * If available, the cache will be used.
133 * \return the number of bytes read.
135 static size_t diskRead(struct BattFsSuper *disk, pgcnt_t page, pgaddr_t addr, void *buf, size_t size)
137 /* Try to read from cache */
138 if (page == disk->curr_page)
139 return disk->bufferRead(disk, addr, buf, size);
142 return disk->read(disk, page, addr, buf, size);
147 * Read header of \a page in \a hdr.
148 * \return true on success, false otherwise.
150 static bool readHdr(struct BattFsSuper *disk, pgcnt_t page, struct BattFsPageHeader *hdr)
152 uint8_t buf[BATTFS_HEADER_LEN];
154 * Read header from disk.
155 * Header is actually a footer, and so
156 * resides at page end.
158 if (diskRead(disk, page, disk->page_size - BATTFS_HEADER_LEN, buf, BATTFS_HEADER_LEN)
159 != BATTFS_HEADER_LEN)
161 LOG_ERR("page[%d]\n", page);
166 disk_to_battfs(buf, hdr);
172 * Set header on current \a disk page buffer.
173 * \return true on success, false otherwise.
175 static bool setBufferHdr(struct BattFsSuper *disk, struct BattFsPageHeader *hdr)
177 uint8_t buf[BATTFS_HEADER_LEN];
179 #warning FIXME:refactor computeFcs to save time and stack
180 hdr->fcs = computeFcs(hdr);
182 battfs_to_disk(hdr, buf);
185 * write header to buffer.
186 * Header is actually a footer, and so
187 * resides at page end.
189 if (disk->bufferWrite(disk, disk->page_size - BATTFS_HEADER_LEN, buf, BATTFS_HEADER_LEN)
190 != BATTFS_HEADER_LEN)
192 LOG_ERR("writing to buffer\n");
199 * Count the number of pages from
200 * inode 0 to \a inode in \a filelen_table.
202 static pgcnt_t countPages(pgoff_t *filelen_table, inode_t inode)
206 for (inode_t i = 0; i < inode; i++)
207 cnt += filelen_table[i];
213 * Move all pages in page allocation array from \a src to \a src + \a offset.
214 * The number of pages moved is page_count - MAX(dst, src).
216 static void movePages(struct BattFsSuper *disk, pgcnt_t src, int offset)
218 pgcnt_t dst = src + offset;
219 LOG_INFO("src %d, offset %d, size %ld\n", src, offset, (disk->page_count - MAX(dst, src)) * sizeof(pgcnt_t));
220 memmove(&disk->page_array[dst], &disk->page_array[src], (disk->page_count - MAX(dst, src)) * sizeof(pgcnt_t));
224 /* Fill empty space in array with sentinel */
225 for (pgcnt_t page = disk->page_count + offset; page < disk->page_count; page++)
226 disk->page_array[page] = PAGE_UNSET_SENTINEL;
231 * Count number of pages per file on \a disk.
232 * This information is registered in \a filelen_table.
233 * Array index represent file inode, while value contained
234 * is the number of pages used by that file.
236 * \return true if ok, false on disk read errors.
237 * \note The whole disk is scanned once.
239 static bool countDiskFilePages(struct BattFsSuper *disk, pgoff_t *filelen_table)
241 BattFsPageHeader hdr;
242 disk->free_page_start = 0;
244 /* Count the number of disk page per file */
245 for (pgcnt_t page = 0; page < disk->page_count; page++)
247 if (!readHdr(disk, page, &hdr))
250 /* Increase free space */
251 disk->free_bytes += disk->page_size - BATTFS_HEADER_LEN;
253 /* Check header FCS */
254 if (hdr.fcs == computeFcs(&hdr))
256 ASSERT(hdr.fill <= disk->page_size - BATTFS_HEADER_LEN);
258 /* Page is valid and is owned by a file */
259 filelen_table[hdr.inode]++;
261 /* Keep trace of free space */
262 disk->free_bytes -= hdr.fill;
263 disk->free_page_start++;
266 LOG_INFO("free_bytes:%d, free_page_start:%d\n", disk->free_bytes, disk->free_page_start);
272 * Fill page allocation array of \a disk
273 * using file lenghts in \a filelen_table.
275 * The page allocation array is an array containings all file infos.
276 * Is ordered by file, and within each file is ordered by page offset
278 * e.g. : at page array[0] you will find page address of the first page
279 * of the first file (if present).
280 * Free blocks are allocated after the last file.
282 * \return true if ok, false on disk read errors.
283 * \note The whole disk is scanned at max twice.
285 static bool fillPageArray(struct BattFsSuper *disk, pgoff_t *filelen_table)
287 BattFsPageHeader hdr;
288 pgcnt_t curr_free_page = disk->free_page_start;
289 /* Fill page allocation array */
290 for (pgcnt_t page = 0; page < disk->page_count; page++)
292 if (!readHdr(disk, page, &hdr))
295 /* Check header FCS */
296 if (hdr.fcs == computeFcs(&hdr))
298 /* Compute array position */
299 pgcnt_t array_pos = countPages(filelen_table, hdr.inode);
300 array_pos += hdr.pgoff;
303 /* Check if position is already used by another page of the same file */
304 if (disk->page_array[array_pos] == PAGE_UNSET_SENTINEL)
305 disk->page_array[array_pos] = page;
308 BattFsPageHeader hdr_prv;
310 if (!readHdr(disk, disk->page_array[array_pos], &hdr_prv))
313 /* Check header FCS */
314 ASSERT(hdr_prv.fcs == computeFcs(&hdr_prv));
316 /* Only the very same page with a different seq number can be here */
317 ASSERT(hdr.inode == hdr_prv.inode);
318 ASSERT(hdr.pgoff == hdr_prv.pgoff);
319 ASSERT(hdr.seq != hdr_prv.seq);
321 pgcnt_t new_page, old_page;
325 * Sequence number comparison: since
326 * seq is 40 bits wide, it wraps once
327 * every 1.1E12 times.
328 * The memory will not live enough to
329 * see a wraparound, so we can use a simple
332 if (hdr.seq > hdr_prv.seq)
334 /* Current header is newer than the previuos one */
335 old_page = disk->page_array[array_pos];
337 old_fill = hdr_prv.fill;
341 /* Previous header is newer than the current one */
343 new_page = disk->page_array[array_pos];
348 disk->page_array[array_pos] = new_page;
350 disk->free_bytes += old_fill;
351 /* Shift all array one position to the left, overwriting duplicate page */
352 array_pos -= hdr.pgoff;
353 array_pos += filelen_table[hdr.inode];
354 movePages(disk, array_pos, -1);
355 /* Move back all indexes */
356 filelen_table[hdr.inode]--;
357 disk->free_page_start--;
359 /* Set old page as free */
360 ASSERT(disk->page_array[curr_free_page] == PAGE_UNSET_SENTINEL);
361 disk->page_array[curr_free_page++] = old_page;
367 /* Invalid page, keep as free */
368 ASSERT(disk->page_array[curr_free_page] == PAGE_UNSET_SENTINEL);
369 LOG_INFO("Page %d invalid, keeping as free\n", page);
370 disk->page_array[curr_free_page++] = page;
378 * Flush the current \a disk buffer.
379 * \return true if ok, false on errors.
381 static bool flushBuffer(struct BattFsSuper *disk)
383 if (disk->cache_dirty)
385 LOG_INFO("Flushing to disk page %d\n", disk->curr_page);
387 if (!(setBufferHdr(disk, &disk->curr_hdr)
388 && disk->erase(disk, disk->curr_page)
389 && disk->save(disk, disk->curr_page)))
392 disk->cache_dirty = false;
398 * Load \a new_page from \a disk in disk page buffer.
399 * If a previuos page is still dirty in the buffer, will be
401 * \return true if ok, false on errors.
403 static bool loadPage(struct BattFsSuper *disk, pgcnt_t new_page)
405 if (disk->curr_page == new_page)
408 LOG_INFO("Loading page %d\n", new_page);
410 if (!(flushBuffer(disk)
411 && disk->load(disk, new_page)))
414 disk->curr_page = new_page;
416 /* Load current header */
417 if (!readHdr(disk, disk->curr_page, &disk->curr_hdr))
425 * Initialize and mount disk described by
427 * \return false on errors, true otherwise.
429 bool battfs_init(struct BattFsSuper *disk)
431 pgoff_t filelen_table[BATTFS_MAX_FILES];
436 /* Init disk device */
437 if (!disk->open(disk))
439 LOG_ERR("open error\n");
443 /* Disk open must set all of these */
446 ASSERT(disk->bufferWrite);
447 ASSERT(disk->bufferRead);
451 ASSERT(disk->page_size);
452 ASSERT(disk->page_count);
453 ASSERT(disk->page_count < PAGE_UNSET_SENTINEL - 1);
454 ASSERT(disk->page_array);
456 memset(filelen_table, 0, BATTFS_MAX_FILES * sizeof(pgoff_t));
458 disk->free_bytes = 0;
459 disk->disk_size = (disk_size_t)(disk->page_size - BATTFS_HEADER_LEN) * disk->page_count;
461 /* Initialize page buffer cache */
462 disk->cache_dirty = false;
464 disk->load(disk, disk->curr_page);
465 readHdr(disk, disk->curr_page, &disk->curr_hdr);
467 /* Count pages per file */
468 if (!countDiskFilePages(disk, filelen_table))
470 LOG_ERR("counting file pages\n");
474 /* Once here, we have filelen_table filled with file lengths */
476 /* Fill page array with sentinel */
477 for (pgcnt_t page = 0; page < disk->page_count; page++)
478 disk->page_array[page] = PAGE_UNSET_SENTINEL;
480 /* Fill page allocation array using filelen_table */
481 if (!fillPageArray(disk, filelen_table))
483 LOG_ERR("filling page array\n");
486 #if LOG_LEVEL > LOG_LVL_INFO
489 #warning TODO: shuffle free blocks
490 //#if LOG_LEVEL > LOG_LVL_INFO
491 // dumpPageArray(disk)
493 /* Init list for opened files. */
494 LIST_INIT(&disk->file_opened_list);
500 * \return 0 if ok, EOF on errors.
502 static int battfs_flush(struct KFile *fd)
504 BattFs *fdb = BATTFS_CAST(fd);
506 if (flushBuffer(fdb->disk))
514 * \return 0 if ok, EOF on errors.
516 static int battfs_fileclose(struct KFile *fd)
518 BattFs *fdb = BATTFS_CAST(fd);
526 static bool getNewPage(struct BattFsSuper *disk, pgcnt_t new_pos, inode_t inode, pgoff_t pgoff)
528 if (disk->free_page_start >= disk->page_count)
530 #warning TODO space over!
531 LOG_INFO("No disk space available\n");
535 LOG_INFO("Getting new page %d, pos %d\n", disk->page_array[disk->free_page_start], new_pos);
536 disk->curr_page = disk->page_array[disk->free_page_start++];
537 memmove(&disk->page_array[new_pos + 1], &disk->page_array[new_pos], (disk->free_page_start - new_pos - 1) * sizeof(pgcnt_t));
540 /* Move following file start point one position ahead. */
541 FOREACH_NODE(n, &disk->file_opened_list)
543 BattFs *file = containerof(n, BattFs, link);
544 if (file->inode > inode)
546 LOG_INFO("Move file %d start pos\n", file->inode);
551 disk->page_array[new_pos] = disk->curr_page;
552 disk->cache_dirty = true;
554 disk->curr_hdr.inode = inode;
555 disk->curr_hdr.pgoff = pgoff;
556 disk->curr_hdr.fill = 0;
557 disk->curr_hdr.seq = 0;
558 setBufferHdr(disk, &disk->curr_hdr);
563 * Write to file \a fd \a size bytes from \a buf.
564 * \return The number of bytes written.
566 static size_t battfs_write(struct KFile *fd, const void *_buf, size_t size)
568 BattFs *fdb = BATTFS_CAST(fd);
569 const uint8_t *buf = (const uint8_t *)_buf;
571 size_t total_write = 0;
573 pgaddr_t addr_offset;
576 #warning TODO seek_pos > size?
580 pg_offset = fd->seek_pos / (fdb->disk->page_size - BATTFS_HEADER_LEN);
581 addr_offset = fd->seek_pos % (fdb->disk->page_size - BATTFS_HEADER_LEN);
582 wr_len = MIN(size, (size_t)(fdb->disk->page_size - BATTFS_HEADER_LEN - addr_offset));
584 /* Handle write outside EOF */
585 if (pg_offset > fdb->max_off)
587 LOG_INFO("New page needed, pg_offset %d, pos %d\n", pg_offset, (fdb->start - fdb->disk->page_array) + pg_offset);
588 if (!getNewPage(fdb->disk, (fdb->start - fdb->disk->page_array) + pg_offset, fdb->inode, pg_offset))
590 fdb->max_off = pg_offset;
592 /* Handle cache load of a new page*/
593 else if (fdb->start[pg_offset] != fdb->disk->curr_page)
595 LOG_INFO("Re-writing page %d to %d\n", fdb->start[pg_offset], fdb->disk->page_array[fdb->disk->free_page_start]);
596 if (!loadPage(fdb->disk, fdb->start[pg_offset]))
598 #warning TODO set error?
602 /* Get a free page */
603 fdb->disk->curr_page = fdb->disk->page_array[fdb->disk->free_page_start];
604 movePages(fdb->disk, fdb->disk->free_page_start + 1, -1);
606 /* Insert previous page in free blocks list */
607 LOG_INFO("Setting page %d as free\n", fdb->start[pg_offset]);
608 fdb->disk->page_array[fdb->disk->page_count - 1] = fdb->start[pg_offset];
609 /* Assign new page */
610 fdb->start[pg_offset] = fdb->disk->curr_page;
611 fdb->disk->curr_hdr.seq++;
615 //LOG_INFO("writing to buffer for page %d, offset %d, size %d\n", fdb->disk->curr_page, addr_offset, wr_len);
616 if (fdb->disk->bufferWrite(fdb->disk, addr_offset, buf, wr_len) != wr_len)
618 #warning TODO set error?
620 fdb->disk->cache_dirty = true;
623 fd->seek_pos += wr_len;
624 total_write += wr_len;
626 fill_t fill_delta = MAX((int32_t)(addr_offset + wr_len) - fdb->disk->curr_hdr.fill, (int32_t)0);
627 fdb->disk->free_bytes -= fill_delta;
628 fdb->disk->curr_hdr.fill += fill_delta;
629 fd->size += fill_delta;
630 //LOG_INFO("free_bytes %d, seek_pos %d, size %d, curr_hdr.fill %d\n", fdb->disk->free_bytes, fd->seek_pos, fd->size, fdb->disk->curr_hdr.fill);
637 * Read from file \a fd \a size bytes in \a buf.
638 * \return The number of bytes read.
640 static size_t battfs_read(struct KFile *fd, void *_buf, size_t size)
642 BattFs *fdb = BATTFS_CAST(fd);
643 uint8_t *buf = (uint8_t *)_buf;
645 size_t total_read = 0;
647 pgaddr_t addr_offset;
650 size = MIN((kfile_off_t)size, fd->size - fd->seek_pos);
654 pg_offset = fd->seek_pos / (fdb->disk->page_size - BATTFS_HEADER_LEN);
655 addr_offset = fd->seek_pos % (fdb->disk->page_size - BATTFS_HEADER_LEN);
656 read_len = MIN(size, (size_t)(fdb->disk->page_size - BATTFS_HEADER_LEN - addr_offset));
659 if (diskRead(fdb->disk, fdb->start[pg_offset], addr_offset, buf, read_len) != read_len)
661 #warning TODO set error?
665 BattFsPageHeader hdr;
666 readHdr(fdb->disk, fdb->start[pg_offset], &hdr);
667 ASSERT(hdr.inode == fdb->inode);
671 fd->seek_pos += read_len;
672 total_read += read_len;
680 * Search file \a inode in \a disk using a binary search.
681 * \a last is filled with array offset of file start
682 * in disk->page_array if file is found, otherwise
683 * \a last is filled with the correct insert position
684 * for creating a file with the given \a inode.
685 * \return true if file is found, false otherwisr.
687 static bool findFile(BattFsSuper *disk, inode_t inode, pgcnt_t *last)
689 BattFsPageHeader hdr;
690 pgcnt_t first = 0, page;
691 *last = disk->free_page_start;
694 while (first < *last)
696 page = (first + *last) / 2;
697 LOG_INFO("first %d, last %d, page %d\n", first, *last, page);
698 if (!readHdr(disk, disk->page_array[page], &hdr))
700 LOG_INFO("inode read: %d\n", hdr.inode);
701 fcs = computeFcs(&hdr);
702 if (hdr.fcs == fcs && hdr.inode == inode)
704 *last = page - hdr.pgoff;
705 LOG_INFO("Found: %d\n", *last);
708 else if (hdr.fcs == fcs && hdr.inode < inode)
713 LOG_INFO("Not found: last %d\n", *last);
718 * \return true if file \a inode exists on \a disk, false otherwise.
720 bool battfs_fileExists(BattFsSuper *disk, inode_t inode)
723 return findFile(disk, inode, &dummy);
727 * Count size of file \a inode on \a disk, starting at pointer \a start
728 * in disk->page_array. Size is written in \a size.
729 * \return true if all s ok, false on disk read errors.
731 static file_size_t countFileSize(BattFsSuper *disk, pgcnt_t *start, inode_t inode)
733 file_size_t size = 0;
734 BattFsPageHeader hdr;
736 while (start < &disk->page_array[disk->free_page_start])
738 if (!readHdr(disk, *start++, &hdr))
740 if (hdr.fcs == computeFcs(&hdr) && hdr.inode == inode)
749 * Open file \a inode from \a disk in \a mode.
750 * File context is stored in \a fd.
751 * \return true if ok, false otherwise.
753 bool battfs_fileopen(BattFsSuper *disk, BattFs *fd, inode_t inode, filemode_t mode)
757 memset(fd, 0, sizeof(*fd));
759 /* Search file start point in disk page array */
761 if (!findFile(disk, inode, &start_pos))
763 LOG_INFO("file %d not found\n", inode);
764 if (!(mode & BATTFS_CREATE))
766 /* Create the file */
767 if (!(getNewPage(disk, start_pos, inode, 0)))
770 fd->start = &disk->page_array[start_pos];
771 LOG_INFO("Start pos %d\n", start_pos);
774 if ((fd->fd.size = countFileSize(disk, fd->start, inode)) == EOF)
776 fd->max_off = fd->fd.size / (disk->page_size - BATTFS_HEADER_LEN);
778 /* Reset seek position */
781 /* Insert file handle in list, ordered by inode, ascending. */
782 FOREACH_NODE(n, &disk->file_opened_list)
784 BattFs *file = containerof(n, BattFs, link);
785 if (file->inode >= inode)
788 INSERT_BEFORE(&fd->link, n);
795 fd->fd.close = battfs_fileclose;
796 fd->fd.flush = battfs_flush;
797 fd->fd.read = battfs_read;
798 fd->fd.reopen = kfile_genericReopen;
799 fd->fd.seek = kfile_genericSeek;
800 fd->fd.write = battfs_write;
802 #warning TODO battfs_error, battfs_clearerr
804 fd->fd.error = battfs_error;
805 fd->fd.clearerr = battfs_clearerr;
808 DB(fd->fd._type = KFT_BATTFS);
816 bool battfs_close(struct BattFsSuper *disk)
821 /* Close all open files */
822 FOREACH_NODE(n, &disk->file_opened_list)
824 BattFs *file = containerof(n, BattFs, link);
825 res += battfs_fileclose(&file->fd);
829 return disk->close(disk) && (res == 0);
834 bool battfs_writeTestBlock(struct BattFsSuper *disk, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff)
836 BattFsPageHeader hdr;
838 /* Reset page to all 0xff */
839 uint8_t buf[disk->page_size];
840 memset(buf, 0xFF, disk->page_size);
841 disk->bufferWrite(disk, 0, buf, disk->page_size);
847 hdr.fcs = computeFcs(&hdr);
849 if (!(setBufferHdr(disk, &hdr) && disk->save(disk, page)))
851 LOG_ERR("error writing hdr\n");