*
* -->
*
- * \version $Id:$
+ * \version $Id$
*
* \author Francesco Sacchi <batt@develer.com>
*
#include <cfg/compiler.h> // uintXX_t; STATIC_ASSERT
#include <cpu/types.h> // CPU_BITS_PER_CHAR
+#include <algo/rotating_hash.h>
+#include <mware/list.h>
+#include <kern/kfile.h>
-typedef uint16_t fill_t;
-typedef uint16_t pgoff_t;
-typedef pgoff_t mark_t;
-typedef uint8_t inode_t;
-typedef uint8_t seq_t;
-typedef uint16_t fcs_t;
+typedef uint16_t fill_t; ///< Type for keeping trace of space filled inside a page
+typedef fill_t pgaddr_t; ///< Type for addressing space inside a page
+typedef uint16_t pgcnt_t; ///< Type for counting pages on disk
+typedef pgcnt_t pgoff_t; ///< Type for counting pages inside a file
+typedef uint32_t mark_t; ///< Type for marking pages as free
+typedef uint8_t inode_t; ///< Type for file inodes
+typedef uint8_t seq_t; ///< Type for page seq number
+typedef rotating_t fcs_t; ///< Type for header FCS.
/**
- * BattFS page header.
- * \note fields order is chosen to comply
- * with CPU alignment.
+ * Size required for free block allocation is at least 1 bit more
+ * than page addressing.
+ */
+STATIC_ASSERT(sizeof(mark_t) > sizeof(pgcnt_t));
+
+/**
+ * BattFS page header, used to represent a page
+ * header in memory.
+ * To see how this is stored on disk:
+ * \see battfs_to_disk
+ * \see disk_to_battfs
*/
typedef struct BattFsPageHeader
{
inode_t inode; ///< File inode (file identifier).
seq_t seq; ///< Page sequence number.
- mark_t mark; ///< Marker used to keep trace of free/used pages.
- pgoff_t pgoff; ///< Page offset inside file.
fill_t fill; ///< Filled bytes in page.
- uint16_t rfu; ///< Reserved for future use, 0xFFFF for now.
- fcs_t fcs; ///< FCS (Frame Check Sequence) of the page header.
+ pgoff_t pgoff; ///< Page offset inside file.
+ mark_t mark; ///< Marker used to keep trace of free/used pages.
+
+ /**
+ * FCS (Frame Check Sequence) of the page header once the page
+ * as been marked as free.
+ */
+ fcs_t fcs_free;
+
+ /**
+ * FCS (Frame Check Sequence) of the page header.
+ */
+ fcs_t fcs;
} BattFsPageHeader;
-/* Ensure structure has no padding added */
-STATIC_ASSERT(sizeof(BattFsPageHeader) == 12);
+/**
+ * Size of the header once saved on disk.
+ * \see battfs_to_disk
+ * \see disk_to_battfs
+ */
+#define BATTFS_HEADER_LEN 12
+
+/**
+ * Marks for valid pages.
+ * Simply set to 1 all field bits.
+ * \{
+ */
+#define MARK_PAGE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1)) - 1)
+#define FCS_FREE_VALID ((1 << (CPU_BITS_PER_CHAR * sizeof(fcs_t))) - 1)
+/* \} */
+
+
+/**
+ * Half-size of free page marker.
+ * Used to keep trace of free marker wrap-arounds.
+ */
+#define MARK_HALF_SIZE (1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t) + 1))
+
+/**
+ * Maximum page address.
+ */
+#define MAX_PAGE_ADDR ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1)
+
+/**
+ * Max number of files.
+ */
+#define BATTFS_MAX_FILES (1 << (CPU_BITS_PER_CHAR * sizeof(inode_t)))
/* Fwd decl */
struct BattFsSuper;
/**
- * Type for disk page addressing.
+ * Sentinel used to keep trace of unset pages in disk->page_array.
*/
-typedef uint32_t battfs_page_t;
+#define PAGE_UNSET_SENTINEL ((1 << (CPU_BITS_PER_CHAR * sizeof(pgcnt_t))) - 1)
/**
* Type interface for disk init function.
* \return true if all is ok, false otherwise.
*/
-typedef bool (*disk_init_t) (struct BattFsSuper *d);
+typedef bool (*disk_open_t) (struct BattFsSuper *d);
/**
* Type interface for disk page read function.
- * \a page is the page address, \a size the lenght to be read.
+ * \a page is the page address, \a addr the address inside the page,
+ * \a size the lenght to be read.
* \return the number of bytes read.
*/
-typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, void *buf, battfs_page_t page, size_t size);
+typedef size_t (*disk_page_read_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, void *buf, size_t);
/**
* Type interface for disk page write function.
- * \a page is the page address, \a size the lenght to be written.
+ * \a page is the page address, \a addr the address inside the page,
+ * \a size the lenght to be written.
* \return the number of bytes written.
*/
-typedef size_t (*disk_page_write_t) (struct BattFsSuper *d, const void *buf, battfs_page_t page, size_t size);
+typedef size_t (*disk_page_write_t) (struct BattFsSuper *d, pgcnt_t page, pgaddr_t addr, const void *buf, size_t);
/**
* Type interface for disk page erase function.
* \a page is the page address.
* \return true if all is ok, false otherwise.
*/
-typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, battfs_page_t page);
+typedef bool (*disk_page_erase_t) (struct BattFsSuper *d, pgcnt_t page);
+
+/**
+ * Type interface for disk deinit function.
+ * \return true if all is ok, false otherwise.
+ */
+typedef bool (*disk_close_t) (struct BattFsSuper *d);
+
typedef uint32_t disk_size_t; ///< Type for disk sizes.
*/
typedef struct BattFsSuper
{
- disk_init_t init; ///< Disk init.
+ disk_open_t open; ///< Disk init.
disk_page_read_t read; ///< Page read.
disk_page_write_t write; ///< Page write.
disk_page_erase_t erase; ///< Page erase.
+ disk_close_t close; ///< Disk deinit.
+
+ pgaddr_t page_size; ///< Size of a disk page, in bytes.
+ pgcnt_t page_count; ///< Number of pages on disk.
+
+ /**
+ * Page allocation array.
+ * This array must be allocated somewhere and
+ * must have enough space for page_count elements.
+ * Is used by the filesystem to represent
+ * the entire disk in memory.
+ */
+ pgcnt_t *page_array;
- disk_size_t disk_size; ///< Size of the disk, in bytes.
+ /**
+ * Lowest free page counter.
+ * This is the counter of the first availble free page.
+ */
+ mark_t free_start;
+
+ /**
+ * Highest free page counter.
+ * This value is the next to be used to mark a block as free.
+ */
+ mark_t free_next;
+
+ disk_size_t disk_size; ///< Size of the disk, in bytes (page_count * page_size).
disk_size_t free_bytes; ///< Free space on the disk.
+
+ List file_opened_list; ///< List used to keep trace of open files.
/* TODO add other fields. */
} BattFsSuper;
+typedef uint8_t filemode_t; ///< Type for file open modes.
+typedef uint32_t file_size_t; ///< Type for file sizes.
+
+/**
+ * Modes for battfs_fileopen.
+ * \{
+ */
+#define BATTFS_CREATE BV(0) ///< Create file if does not exist
+#define BATTFS_RD BV(1) ///< Open file for reading
+#define BATTFS_WR BV(2) ///< Open file fir writing
+/*/}*/
+
+
+/**
+ * Describe a BattFs file usign a KFile.
+ */
+typedef struct KFileBattFs
+{
+ KFile fd; ///< KFile context
+ Node link; ///< Link for inserting in opened file list
+ inode_t inode; ///< inode of the opened file
+ BattFsSuper *disk; ///< Disk context
+ filemode_t mode; ///< File open mode
+ pgcnt_t *start; ///< Pointer to page_array file start position.
+} KFileBattFs;
+
+/**
+ * Id for battfs file descriptors.
+ */
+#define KFT_BATTFS MAKE_ID('B', 'T', 'F', 'S')
+
+/**
+ * Macro used to cast a KFile to a KFileBattFs.
+ * Also perform dynamic type check.
+ */
+INLINE KFileBattFs * KFILEBATTFS(KFile *fd)
+{
+ ASSERT(fd->_type == KFT_BATTFS);
+ return (KFileBattFs *)fd;
+}
+
+bool battfs_init(struct BattFsSuper *d);
+bool battfs_close(struct BattFsSuper *disk);
+
+bool battfs_fileExists(BattFsSuper *disk, inode_t inode);
+bool battfs_fileopen(BattFsSuper *disk, KFileBattFs *fd, inode_t inode, filemode_t mode);
+
+bool battfs_writeTestBlock(struct BattFsSuper *disk, pgcnt_t page, inode_t inode, seq_t seq, fill_t fill, pgoff_t pgoff, mark_t mark);
+
#endif /* FS_BATTFS_H */
projects / bertos.git / blobdiff