#include <mware/byteorder.h> /* cpu_to_xx */
-#include <string.h> /* memset */
+#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.
STATIC_ASSERT(sizeof(hdr->inode) == 1);
STATIC_ASSERT(sizeof(hdr->seq) == 1);
- STATIC_ASSERT(sizeof(hdr->mark) == 2);
- hdr->mark = cpu_to_le16(hdr->mark);
+ 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->inode) == 1);
STATIC_ASSERT(sizeof(hdr->seq) == 1);
- STATIC_ASSERT(sizeof(hdr->mark) == 2);
- hdr->mark = le16_to_cpu(hdr->mark);
+ hdr->mark = mark_t_to_cpu(hdr->mark);
STATIC_ASSERT(sizeof(hdr->fill) == 2);
hdr->fill = le16_to_cpu(hdr->fill);
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 free_number, pgcnt_t page)
+{
+ ASSERT(free_number >= disk->min_free);
+ ASSERT(free_number <= 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.
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");
+ TRACEMSG("open error\n");
return false;
}
if (cks == hdr.fcs)
{
/* Page is valid and is owned by a file */
- ASSERT(hdr.inode != BATTFS_FREE_INODE);
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 */
- filelen_table[BATTFS_FREE_INODE]++;
disk->free_bytes += disk->page_size - sizeof(BattFsPageHeader);
- /* Check if putting mark to MARK_PAGE_VALID makes fcs correct */
+ /* Check if setting mark to MARK_PAGE_VALID makes fcs correct */
mark_t old_mark = hdr.mark;
hdr.mark = MARK_PAGE_VALID;
rotating_init(&cks);
disk->max_free = MAX(disk->max_free, old_mark);
}
else
- TRACEMSG("Page [%d] invalid, keeping as free\n", page);
+ TRACEMSG("page [%d] invalid, keeping as free\n", page);
}
}
/* Once here, we have filelen_table filled with file lengths */
- #warning Complete me!
-
+ /* 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) - 1))
+ 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 setting 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