#include "battfs.h"
+#include <cfg/debug.h>
+#include <cfg/macros.h> /* MIN, MAX */
#include <mware/byteorder.h> /* cpu_to_xx */
-#include <string.h> /* memset */
+
+#include <string.h> /* memset, memmove */
+
/**
- * Convert from cpu endianess to filesystem endianness.
+ * Convert from memory representation to disk structure.
* \note filesystem is in little-endian format.
*/
-INLINE void cpu_to_battfs(struct BattFsPageHeader *hdr)
+INLINE void battfs_to_disk(struct BattFsPageHeader *hdr, uint8_t *buf)
{
- STATIC_ASSERT(sizeof(hdr->inode) == 1);
- STATIC_ASSERT(sizeof(hdr->seq) == 1);
+ STATIC_ASSERT(BATTFS_HEADER_LEN == 13);
+ buf[0] = hdr->inode;
- STATIC_ASSERT(sizeof(hdr->mark) == 2);
- hdr->mark = cpu_to_le16(hdr->mark);
+ buf[1] = hdr->seq;
- STATIC_ASSERT(sizeof(hdr->fill) == 2);
- hdr->fill = cpu_to_le16(hdr->fill);
+ buf[2] = hdr->fill;
+ buf[3] = hdr->fill >> 8;
- STATIC_ASSERT(sizeof(hdr->pgoff) == 2);
- hdr->pgoff = cpu_to_le16(hdr->pgoff);
+ buf[4] = hdr->pgoff;
+ buf[5] = hdr->pgoff >> 8;
- STATIC_ASSERT(sizeof(hdr->fcs) == 2);
- hdr->fcs = cpu_to_le16(hdr->fcs);
+ /*
+ * Mark is at least 1 bit longer than page address.
+ * Needed to take care of wraparonds.
+ */
+ buf[6] = hdr->mark;
+ buf[7] = hdr->mark >> 8;
+ buf[8] = hdr->mark >> 16;
- STATIC_ASSERT(sizeof(hdr->rfu) == 2);
- hdr->rfu = cpu_to_le16(hdr->rfu);
-}
+ /*
+ * This field must be the before the last one!
+ */
+ buf[9] = hdr->fcs_free;
+ buf[10] = 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[11] = hdr->fcs;
+ buf[12] = hdr->fcs >> 8;
+}
/**
- * Convert from filesystem endianness to cpu endianess.
+ * Convert from disk structure to memory representation.
* \note filesystem is in little-endian format.
*/
-INLINE void battfs_to_cpu(struct BattFsPageHeader *hdr)
+INLINE void disk_to_battfs(uint8_t *buf, struct BattFsPageHeader *hdr)
{
- STATIC_ASSERT(sizeof(hdr->inode) == 1);
- STATIC_ASSERT(sizeof(hdr->seq) == 1);
-
- STATIC_ASSERT(sizeof(hdr->mark) == 2);
- hdr->mark = le16_to_cpu(hdr->mark);
+ STATIC_ASSERT(BATTFS_HEADER_LEN == 13);
+ hdr->inode = buf[0];
+ hdr->seq = buf[1];
+ hdr->fill = buf[3] << 8 | buf[2];
+ hdr->pgoff = buf[5] << 8 | buf[4];
+ hdr->mark = (mark_t)buf[8] << 16 | buf[7] << 8 | buf[6];
+ hdr->fcs_free = buf[10] << 8 | buf[9];
+ hdr->fcs = buf[12] << 8 | buf[11];
+}
- STATIC_ASSERT(sizeof(hdr->fill) == 2);
- hdr->fill = le16_to_cpu(hdr->fill);
+/**
+ * Compute the fcs of the header.
+ */
+static fcs_t computeFcs(struct BattFsPageHeader *hdr)
+{
+ uint8_t buf[BATTFS_HEADER_LEN];
+ fcs_t cks;
- STATIC_ASSERT(sizeof(hdr->pgoff) == 2);
- hdr->pgoff = le16_to_cpu(hdr->pgoff);
+ 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;
+}
- STATIC_ASSERT(sizeof(hdr->fcs) == 2);
- hdr->fcs = le16_to_cpu(hdr->fcs);
+/**
+ * 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;
- STATIC_ASSERT(sizeof(hdr->rfu) == 2);
- hdr->rfu = le16_to_cpu(hdr->rfu);
+ 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;
}
*/
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
+ * 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))
+ 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);
- /* 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 compute position.
+ */
+static void insertFreePage(struct BattFsSuper *disk, pgoff_t *filelen_table, mark_t mark, pgcnt_t page)
+{
+ ASSERT(mark >= disk->free_start);
+ ASSERT(mark < disk->free_next);
+
+ pgcnt_t free_pos = countPages(filelen_table, BATTFS_MAX_FILES - 1);
+ free_pos += mark - disk->free_start;
+ TRACEMSG("mark:%d, page:%d, free_start:%d, free_next:%d, free_pos:%d\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.
bool battfs_init(struct BattFsSuper *disk)
{
BattFsPageHeader hdr;
- rotating_t cks;
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 */
- rotating_init(&cks);
- rotating_update(&hdr, sizeof(BattFsPageHeader) - sizeof(rotating_t), &cks);
- if (cks == hdr.fcs)
- filelen_table[page]++;
+ 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
{
- #warning Finish me!
+ /* 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);
+ maxl = MAX(maxl, 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;
+ }
+
+ /* 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 */
+ #define HALF_SEQ (1 << ((sizeof(seq_t) * CPU_BITS_PER_CHAR) - 1))
+ if ((hdr.seq - hdr_old.seq) < HALF_SEQ)
+ {
+ /* 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, filelen_table, 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 the end of list */
+ hdr.mark = disk->free_next++;
+
+ insertFreePage(disk, filelen_table, hdr.mark, page);
+ }
+ }
+
+ #warning Test me!
return true;
}
projects / bertos.git / blobdiff